GTA
General Discussion To Gateway To Airguns => China Gate => : hyounker December 30, 2008, 02:44:37 AM
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Thanks again to all who have helped me get this far with this old airgun. I really thought I had a piece of junk lying around! We’ll see, in time. I’ve decided to chronicle my tune-up here so that others can critique my work and my results.
Yesterday, I shot the airgun for the first time in about 15 years! I started by cleaning the barrel. I pushed a dry patch through the barrel with a brass jag just to see what came out. The patch was covered with rust, so I pushed a couple more through with some Hoppes Solvent on them. It took awhile, but I finally got a patch to run through clean. I then pushed a patch through with some Remington Oil on it, then several more dry patches followed that.
I shot about 40 rounds of Crosman Premier Hollow Point Hunting Pellets trying to get a feel for the trigger. I hope the trigger can be improved. It is flat out, AWFUL! In its travel, there are three distinct “releasesâ€, the last one firing the piston. Nonetheless, I felt like I could predict its travel well enough to shoot in a consistent manner.
I measured off 50 feet from my shooting bench and hung some targets on a cardboard box. I purchased three different types of pellets locally to try with this airgun. I chronographed 5 rounds of each type with a Chrony Gamma Master and then shot five round groups into targets from 50 feet. The tins did not indicate a pellet weight, so I weighed 20 of each on my digital reloading scale and divided the total by 20 for an average weight. All shots were fired using the factory iron sights. Of course, POI was nowhere near my aiming point with any of the pellets. I don’t think it’s a surprise that the pellet that demonstrated the lowest standard deviation over 5 shots was also the most accurate pellet.
Here’s all the results:
Crosman Premier Hollow Point Hunting Pellet
Average Pellet Weight: 7.9 grains
Chronograph: 552
524
515
538
507
Average fps 527
SD 16
See picture below of Target #1
Group Size: 1.375â€
Daisy Precision Max Premium Grade Pointed Lead Pellet
Average Pellet Weight: 7.2 grains
Chronograph: 563
534
571
544
548
Average fps 552
SD 13
See picture below of Target #2
Group Size: 2.875â€
Crosman Premier Pointed Hunting Pellet
Average Pellet Weight: 7.4 grains
Chronograph: 557
548
559
553
548
Average fps 553
SD 4.5
See picture below of Target #3
Group Size: .8125â€
Anything stand out to you guys, good or bad? Did I do anything stupid? Is there anything else I should do prior to tearing this thing down? Thanks again for all the help.
hyounker
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Well, that hops was not the best idea. Any solvent like that can lead to detonation (use goo gone instead), but based on your #'s, I doubt it is or it would be higher.
There is a rebuild kit you can get from South Summit for about $8, comes with a better spring, trigger sear, piston and breach seal, and fire starter (cheap used oil). That spring will be able to get you up into the 700's if everything else is good. Best $8 you'll spend. If your seal is leather, soak it in some oil (I used 10w30) for a few days and squeeze all the extra you can out when you install. This will lead to detonation for the first 25-50 shots, but after it will calm down and keep the seal nice for a long time. I like the leather better because it fits any deformities better.
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I'm interested in how much improvement you get after tuning on that gun. so, keep us posted.
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I had read about the possibility of detonation with that kind of stuff in the barrel. I literally ran 20 dry patches through that barrel to finish. I was actually more worried about the RemOil that I used to wipe away the Hoppes.
Don't forget, your dealing with an old primer and powder guy here!!! I really had no idea how to clean that barrel the right way. I did some searching, but I couldn't find any real specifics, so I went with what I know! Mistake number one!
Will the kit you mentioned have a replacement for the seal in the picture below? Not sure what it's called, but noticed while cleaning the barrel that it was cracked, then noticed during shooting that pieces had fallen off it.
Again, thanks for the help.
Henry
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Thanks, naildigger! I'm as anxious as anyone!
Henry
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Breach seal, and yes it is included.
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I'm ordering some things to get started on this airgun and have decided to go ahead and order a scope and mount. I am also waiting for a brand new Gamo Whisper to come in the brown truck. What do you call the scope mount dovetail on the B3? And will the Whisper have the same dovetail?
Thanks,
Henry
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If you deside to use one piece mount, pay attention to very short rail on b3.
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scanb3,
Will this work?:
http://www.opticsplanet.net/leapers-airgun-22-1-bi-directional-offset-optimum-profile-mount-rgpmofs38-25h4.html
The base length is only 62mm, as opposed to 100mm for most other Leapers. I measured the B3 and it looks like you have about 3.25" of useable dovetail.
Also, is this dovetail 11mm? And will the Whisper be the same?
Henry
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Henry, I'm not ScanB3, but I'm sure you are looking forward to answers...so if I may, I'd like to jump in.
Yes, I think that offset mount will work on your B3. On mine, the dovetails are approx. 3.25~3.5 inches of usable groove(80~90mm), and you were sayin that yours is about 3.25". If that offset base is only 60mm, then you should be ok. I always ask how you can stop the base from moving though...so there needs to be some kind of stop.
There is always questions about the size of airgun dovetails, and I will venture to say that after measuring my B3, its about 11mm. I cant be precise, because we need a standard for actually measuring the dovetails. One standard is to put a 1mm rod in each grove and then measure the OD between them, but I have no 1mm rod so I just measured the top width.
I'd like to mention to you that you can make your own breech seals out of soft tubing, fuel hose, vinyl hose...I use 5/16" fuel hose. I like the way that seals better than the stock breech seals. My 5/16" fuel hose is about 17/32" OD, 5/16"ID, and about .350" long...got it at ACE Hardware, but lots of places have it. Take out those old peices of seal, push in a new length of hose, close 'er up, and you are there. Might have to experiment with the length though...the trick is to get that baby so that when she closes up there's a slight resistance, which is the loading port cone pushing into the hose/seal, and sealing up in the process. Too long and she wont close properly, too short and she wont seal all the way. With a good breech seal goin on, your velocity/consistency will come up quite a bit...it might be surprising.
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The Whisper has grooves cut into the rcvr just like the B3 and they are about the same size in width. The whisper's grooves are quite a bit longer though, and it has a clamp-on rail that fits into the grooves and acts like a riser somewhat, and also has scopestop pin holes. Here's a pic of the front of the Whisper rail:
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With a hopefully decent B out of the box and some good TLC you should be able to squeeze 600 to 700+ out of one. Ed
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Jumped into the B3 today after finishing up my very rough version of a spring compressor. Worked like a champ though!
Everything went as expected. The surprising thing about the disassembly was that nothing was much of a surprise. All the information that I gathered on this site had me very much prepared for the task. Thanks to all.
I did find one thing inside the ole B3 that looked different from what I expected. During all my reading and research here, I don't remember seeing a spring guide like the one that popped out of my B3. Pictures below. Comments appreciated.
I cleaned all the parts today with mineral spirits and soapy water, then blew them dry with compressed air. I'll start polishing tomorrow and through the weekend as I have time. Still waiting on the kit from South Summit.
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Hey Guys,
I haven't heard anything about that spring guide in my last post. Was hoping to hear if others have seen it before.
Started deburring today and found a problem. Should I fix this broken weld, or is it okay as is? The weld that attaches the rolled steel together on the piston has broken (opposite end from seal end). Seems like conventional wisdom would say to fix it, but I think I've learned to ask you guys before I jump into something like that.
Thanks for any help.
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I don't know if you should weld that...but I have seen the metal spring guide in the XS-B3-1, which looks like a AK47. A well built airgun IMHO.
I have 2 B3s and they both have the plastic spring guide. Metal is not a bad thing...will last much longer in the long run...and Moly clings to it real good!!!
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Seemed to me that it would be better if there was a flat surface for the spring to ride on, instead of that rounded, dome like piece. I'm thinking of machining a spring guide like this to eliminate the plastic cap:
http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=12857&mid=103846#M103846
Hey, BTW, noticed you had a Shadow Express .22 (you've got quite a collection!). I saw one at Wally's World today for $150, on clearance. Worth it? Have you shot the shotshells?
Thanks,
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Oh wow I didn't noticethat the metal one had a rounded spring seat. Yes, flat is better. You can put a washer there and it will work well, and another or two at the piston end.
About the Shadow Express...Well...worth it is up to you. It has a smooth bore, it is not rifled. It is not as accurate as my others with rifled bores. The shotshells are fun, but only at a distance of about 10 feet...maybe 15 max. The shot is small...its #9, so it looses its energy quickly, and the pattern spreads out. Fun for blowin away pests at that close range and thats it. You can reuse the shells and load your own...but still, the range on the shells is a problem. The shotsize needs to be bigger, and more power behind the shot, and then I think we could have some fun. It has a chamber adapter that comes with it that you can shoot regular .22 pellets with it. With pellets, the power is good, but because of the smooth bore, accuracy suffers. Now, I dont want to give you the impression that this is a POS, but for 150 bucks I would kick in an extra $50, buy a Whisper .22 from Midsouth and never look back. Link below:
http://www.midsouthshooterssupply.com/item.asp?sku=0016461100495554 (http://www.midsouthshooterssupply.com/item.asp?sku=0016461100495554)
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Thanks for the tips on the washers. I'll start trying to find some.
I think I'll put this thing back together as close to stock as possible (need to replace breech seal, at a minimum) and see how it feels and shoots, compared to pre-tune. Then go back in and make some of the changes that you and others recommend in this and other threads. I like to tinker! I'm gonna go tomorrow to try to find some of the fuel hose that you (davee1) recommended.
Also, I read here somewhere about the points of the trigger that should be polished, but I can't find it now. It was a diagram with arrows pointing to the areas that should be polished. Can anyone help me find it again?
Smooth bore doesn't sound like me. I'm an accuracy kind of guy. I didn't know that it was a smooth bore, but it makes sense now (shotshells).
Thanks to all,
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http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=11269&mid=87160#M87160
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Excellent...I can't think of a better airgun to tinker with. Most of what you learn can be applied to other airguns as well.
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hyounker - 1/9/2009 7:03 PM
Thanks for the tips on the washers. I'll start trying to find some.
You can find a washer with the right outside diameter for the spring guide but you'll have the increase the inner diameter. I drill it out to make a bigger whole then use a my dremel to finish it and clean it up.
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I might as well say that the washers used should be hardened washers like grade 8. Sometimes you can find stock washers that will work, and sometimes you have to modify them to fit. If you can't find hardened washers, then at least use stainless steel. The idea about this is that the washers take a beating from the spring, so you want them to be able to stand up to that beating. But...its not like if you use regular washers that the washers are gonna break on ya after a few shots...they'll stand upwhile you find some hardened ones. Just don't leave em in there to wear out and let pieces of em get all over the place and ruin everything. Moly is important too. Now before I start into my lecture about making a "bearing", let me just say this: everyone has their own way of doing stuff. This is my way. Embrace it, modify it, totally ignore it...do whatever you want...do whatmakes sense to you.Some folks use 1 washer and some use 2 washers to make abearing...here's how I do it: I put 2 washers at each end of the spring, so there is 2 on the spring guide rod and 2 inside of the piston, and I apply moly to thewashers and ends of the spring. I use some fine sandpaper, like 1200 grit to get a finish on the washers so that the moly has microscopic grooves to get into and do its job...making your bearing nice and slick. You can even have the surface of the washerthat meets the spring ends be finely polished to a mirror shine if you want, but the "sandwich" between the 2 washers should have some fine grooves for the moly to get into. These washers act like a thrust bearing, without any needle bearings or anything like that. The spring is free to twist,turn, and torqueall it wants...but very little of the torqueis actually transmitted into the rest of the airgun. I don't feel any twisting or torque in my B3 that I've tuned and experimentedwith. Sometimes 4 washers total is too much because that spaces up the spring to where it won't cock...if thats the case then use 3, or 2 washers. I've even used more washers than that, and a tophat, just so I can space up the spring to its maximum, which can give you a little more power...YMMV(your mileage may vary).But then we canget into too much weight/too many washers inside of the piston, which makes the piston really heavy, and can add to the recoil, and in really bad cases...cause the piston to "slam".So there's a balance, a tradeoff, but my 4 washershaven't hurt my B3 yet...and literally thousands of pellets have gone out of it. Now, granted, there is a whole lot more to tuning an airgun...but thats what I do with thewashers.(http://../jscripts/tiny_mce/plugins/emotions/images/smiley-smile.gif)
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Great info, guys. Thanks a bunch.
I own a very small company and I lease warehouse space from a machine shop. The guys over there have been great in the past with all my little "needs". They carry a plethora of bronze washers that they call Oilite bearings. When I showed them the spring, piston, spring guide from the B3, they recommended using one Oilite Bearing on each end of the spring, stating that it was a near perfect application of the bearing. Anyone else used these? They also said that polishing was probably unnecessary, as the spring would polish the bronze very quickly.
Any comments on these washers, or should I stick with hardened washers?
THanks again.
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I've used the oil lite bearings and they work fine they are a type of bronze that is impregnated with a lube. They are the same type of bearings you used to see in elect. drills years ago befoer they used needle bearings , thy are still found in cheaper drills .I am only refering to the drills since most of us might have seen this type of bearing their, also they work easy you can drill them easy to fit on a spring guide but you might want to put them between 2 pieces of wood and then drill less chance of breaking them. howie ps I also like 2 thin SS washers with lube between.
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error
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Hey, could I use some sort of delrin-like material for a spacer (eliminating the short rounded piece that contacted the spring originally) and then put washers on top of that?
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Howie,
Thanks for the input. Seeing as the machine shop boys will hand me a few for nothing, I think I'll try it later. I have found, thoughout the years, that the free part is almost always is superior to any other!!!
See my other post below.
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yes, you can use delrin spacers in a B3. But I wouldnt use delrin like in a WFH because of the tremendous forces involved. I have some delrin spacers in my B3. But I prefer to have the springs ends contacting metal washers.
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About those bronze washers...I have an open mind, always looking for a better way to do things. I'm wondering if the bronze washers can stand up to the compression forces generated by the spring. Like for example, Howie mentioned that he's seen the bronzies in drills. In a drill, there's rotational force...much more so than compression force. Its like the perfect solution for things to spin against, but Howie also mentions how brittle they are. Something that brittle might shatter under the forces from the spring. But hey...you could try em. The B3 wont explode on ya from those bronzies. You'd just have ta be keen on listening for abnormalities, feeling for abnormalities, and open it up for periodic inspection. Thats one of the beauties of having/tinkering with a B3...whats the worst that could happen? If the thing breaks on ya, and ya can't fix it...your only out 25 bucks!!! And a new one is only a few keystrokes away(http://../jscripts/tiny_mce/plugins/emotions/images/smiley-smile.gif)
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Why not? His older one has the metal spring guide, but current ones use a plastic, far less strong compared to bronze, and it holds up to the spring.
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70GTvert, I always say...if it don't make sense to you, and no one has any experience to say otherwise...then try it yourself(in this particular case, where your life is not threatened). Whats the worst that would happen? The bronzies wouldnt work, shatter, and have pieces all over the place inside of the B3, or the bronzies might wear away slowly putting bronze dust everywhere. Whats the best that would happen? The bronzies would work and turn out to be an excellent choice, and then hopefully that info would be shared with everyone.
When I drill a hole in delrin...it doesn't break. I don't need to put it between two pieces of wood to keep it from shattering, like what Howie mentioned. That signifies brittleness in my humble opinion. I figure that a brittle material like that is not going to stand up against the compressiveforces inside of a springer in general. If a regular old metal washer gets beat up in a springer, how can a brittle bronze washer hold up?
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Here's McMaster Carr's description of the Oilite Bearings, to further fuel this debate! :
SAE 841 Bronze
Also called Oilite. Porous material impregnated with roughly 18% SAE 30 oil, makes a virtually maintenance-free bearing. Oil acts as a cushion between the bearing and shaft, adding resistance to shock loads (suddenly applied loads) and wear. Use in areas that are difficult to access for maintenance.
SAE 863 Bronze
Also called Super Oilite, this oil-impregnated material is maintenance free like SAE 841, but is made primarily of iron (mixed with copper), which makes it even stronger than SAE 841. Perfect for locations where access to bearings is limited.
After reading this, I would have to say that it is definitely worth a try!!! The surprising thing is that the Super Oilites are cheaper than any other.
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Started putting things back together this morning, and ran into an area that I need clarification on. In Bob's Fast Deer tune guide, he says to use silicone grease inside the compression chamber. But then later, recommends using Charlie's Chamber Oil to occasionally lube the chamber, if you have a leather seal.
Should I use Charlie's Chamber Oil on the inside of the compression chamber when I re-assemble, since I have a leather seal on this B3. Or use the silicone grease for re-assembly and the Charlie's Chamber Oil for later lubes?
Thanks for any help.
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I used a broze looking bearing to space the spring forward. 1/2" i.d. fit over the tube I glued over the spring guide. I had to grind one end down a bit to fit inside the piston.
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I put it back together using Charlie's Chamber Oil on the piston and inside the compression chamber.
Got everything back together, though I had a hard time getting the spring retaining pin back in. It didn't seem to line up well in all four holes. I'm guessing this is probably standard Chinese precision!
I reassembled the rifle with all the original parts. I haven't received my kit from southsummit yet. The only exception is the breach seal. I used a length of fuel hose as suggested by davee1. I may need to cut a slightler shorter length for that later. Also, the plastic washer that was between the leather seal and the piston was broken, and I did not replace that before reassembly.
The cocking motion is now smooth as silk! I was very surprised at how quiet and smooth this became.
I shot a few rounds to watch for dieseling or detonation and those rounds seemed very clean. I shot about 15 rounds into the woods, just to listen and watch. All seemed very smooth and extremely quiet. The spring sound was definitely improved. All I hear now is a gentle thwaaaap. I assume this is normal, though I have never heard a tuned B3 before.
I shot 5 rounds through the chrony and averaged about 530 fps, which is about 30 fps less than I shot prior to disassembly.
Do you think the loss in velocity is due to the new breach seal leaking a little, and/or the missing washer? Or is this normal after a tune? How do I test the breach seal for leaks?
How much improvement can I expect with a new spring from SouthSummit (if they are still in business!!).
Thanks for the help.
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Dave,
Thanks for the tip on the fuel hose. I had to drive all over town to find some (Ace didn't have it), but finally found it at O'Reilly's Auto Parts, a black hose marked as 5/16" radiator overflow hose.
I cut it to about .350" and put it in the pocket around the exhaust port. After closing the action, I got that really smooth "seating" feel. I opened it up and the hose was squished a little and hanging out of the pocket a little. All this sound right? I ask because my velocity is slightly down after the tune and I am wondering how to know if the breach seal is leaking.
Thanks,
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Yep, that sounds about right Henry. What I did was experiment with different lengths of hose until it closed up with a little resistance, and I used the chrony to see if there was any improvement with the different lengths. For example, you could try .400" and see how that does. Some hose should extend out of the seat/pocket so that the top of it can seal against the top of the cone and surrounding surface. You probably already have it right...but experimentation sometimes gives you a few more FPS. Do you have any silicone grease? I use that to lube up the seat and hose, and then push the hose in, then close her up...seems to make the hose a little squishier too.
Did your piston seal slide right in? There should be some resistance there too. But, it does actually work though...its going in excess of 500fps. How old is this B3?
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Henry, did you try spacing up the spring to its max?
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I'll play around with the length. After all, I have three feet of this hose now!!
I do have some silicone grease and I'll try that as I experiment.
The leather seal seemed to be a great seal. Some resistance, but not too much. The seal didn't look the best, but seemed to seal really good. I put my finger over the exhaust port and couldn't move the piston forward if I held it tight.
This rifle is at least 15 years old. I bought this thing at a gun show, shot a few times, then wrote it off as a POS. Been in the closet until about 2 weeks ago!
I have not installed any spacers. I wanted to see where I was with stock parts first.
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The way you tested the piston seal is a good test Henry. If it holds air like that, then we can't do much better than that. Maybe spring spacing, breech seal experimentation, and some more shots may bring the velocity up. I'm only familiar with the B3s from the last few years...mine are in the upper 600~lower 700 fps range. Some of the B3s just dont go too far. I think taking that washer out from between the piston and seal just made more cylinder volume...which is a good thing. Some guys have even shortened their pistons a little too. The possibilities are endless...and we get back to whats the worst that could happen.
I'm going to try to dig up a link where a guy made an adjustable piston seal out of 1/2" and 3/8" flat rubber faucet washers.
The other thing is you must remember, is that you don't have the QF2 spring in there yet, and that will make a difference.
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Here ya go...check outthis document in the link below, and see if there's anything that helps or you want to try. Look for the section about "leather seal expansion washer improvement". You can improve the leather seals tightness against the compression cylinder walls. I've read about others trying this and had some good results. I haven't done it yet, but I plan to.
http://webpages.charter.net/guru1/documents/B-3%20guide%202.0.pdf (http://webpages.charter.net/guru1/documents/B-3%20guide%202.0.pdf)
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I used that document during my tune, along with Bob's Fast Deer Guide.
I decided against the seal mod after my test. But, thinking this over, when that piston slams, my test may be flawed.
Have you seen this link?:
http://www.gatewaytoairguns.com/library/Making%20Leather%20Seals.htm
Pretty cool. I may try this even if I don't need a seal!!! What can I expect from the seal that comes with the kit from southsummit? Can't wait for that spring!
Thanks again for all your help.
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Yep, but so far I haven't had to make a new seal. Henry, the QF2 kit doesn't come with a new leather piston seal. It has a synthetic seal. There's a different better mainspring, two breech seals, a trigger spring, a sear, some oil that you dont wanna use, and some barrel cleaning rods/end fittings. The cleaning rods I don't use for barrel cleaning, but I save em for something someday. One guy uses em to prop up his skyscreens on his chrony.
Now, some have made the conversion to a synthetic piston seal. The results have varied...some see better velocity and others have seen a drop in velocity. The leather seal is much more forgiving about the inconsistencies in the compression chamber, and there's more seal material in general to seal with. Supposedly, the Chinese QC has come a long way in the last few years, and folks say they are putting out better product now. Since yours is like 15 years old, you may have gotten one with a lot of inconsistencies in the chamber...who knows. So if you wanted to convert to a synthetic piston seal, we are back to whats the worst that could happen. An adapter is needed for fitting the synthetic seal to the piston. Its so much easier just to save the synthetic piston seals for some other chinese guns that you may buy in the future that actually use them. My B3AK is such a gun, and I had spare seals on hand because of the QF2 kits that I had bought previously. But hey...thats up to you.
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To test the breach in any air gun what you do is to take a small piece of tissue paper and cover the loading port behind the pellet and shoot the gun if you get one nice round hole everthing is fine if you get a ragged tore type hole you have a leak and the breach seal needs replacement. howie
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Howie,
Great tip. Thanks. I'll give it a try!
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After putting everything back together, and after my last post concerning the possible breach seal leak, I fired about 150 pellets through the rifle. The cocking action deteriorated a little, but still better than before. I guess I need more polishing and more moly?
After the 150 rounds, I chronied several rounds and got an average FPS of 556 with an SD of 13. I was using the Crosman Premier Hollow Points and these values are very similar to the pre-tune values.
Then I disassembled again and added 2 bronze washers (McMaster Carr 5906K512) between the spring and the spring guide. Again, I chronied several rounds and got an average fps of 540 and an SD of 11.
Does any of this mean anything to anyone? What should I do next? I am thinking of installing two of the same washers in the piston. (?) Are these 1/8" changes of any value?
I've got a breach seal test that I will try tomorrow (thanks, Howie!!).
One mistake I made was using the Crosman HPs. Those did not perform well in my original pre-tune testing. I misunderstood my own notes!!! I may try again using the pointed pellets, which performed much better pre-tune.
Any help appreciated?
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The only thing I can think of is more spacers/washers and soaking the piston seal in a preferred oil mixture for said leather seal. You may not be able to get much more out of her until you put that QF2 spring in. Folks generally see 600~700fps after a good tuneup, like Shadow said. Maybe ~550 is all she can put out right now.
The space provided by one or two washers is not that much...the washer's purpose is more about being a bearing than it is a spacer. Use 2 washers at each end of the spring and see how that does. If you can still cock it, add more space...using more washers or some type of spacer. Space the spring up to the max and see if that gives you any gain. Now, I don't have my B3 open right now, but the way I remember it, there was a lot of room in there for spacing.
It also sounds like you are thinking that you might need more moly. Moly is good stuff, but you can get too much of it in there, so be careful. You'll know that youv'e put too much in if she starts heavily smoking with each shot. A little smoke is normal at first after a lubeup, but it should minimize after 10~20 shot cycles. The more excess lube there is, the more smoke there is and the longer it lasts. I just keep shooting to "clear her out", as long as theres no detonations happening. A little smoke is ok too.
And remember that your working with a twenty dollar airgun...so smooth as silk may not last long.
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Howie,
Tried your test today. Seems like no matter what I use, the paper is torn, but it seems like the fuel hose is tearing it as it tightens around the cone. I used tissue, one ply TP, even a lense cleaning cloth. I get a nice smooth hole in the middle, but then tears around that, but mostly to the top.
Your opinion? You want a picture?
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Dave,
I'm gonna add some more spacing as time permits. I'll post results here. Unfortunately, my QF2 kit has been delayed because South Summit is out of stock (they claim to have sent me an email about this when their servers were down!) Ordered another yesterday.
About the lube. I think the only area I will concentrate on, concerning the deteriorating cocking action, is the external parts. Admittedly, I didn't spend much time around the cocking arm and anti-bear trap device. Everything looks good in the receiver/compression chamber/piston area, so I don't think I have any binding there.
How tight should I turn the anti-bear trap screw (the one between the two screws)?
Thanks, again.
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Just hand tool tight, don't try and crank it down, that is fairly soft metal used in these guns. I removed mine. False sense of security. All it does is prevent you from pulling the trigger when in the process of cocking. Can lead to bad habits like keeping finger on or near trigger and they can and do fail, especialy in the cheaper form found on these guns. Plus, it prevents de-cocking. In all of my guns, from my b-3's to my Cat (the Beemans don't have them!) I have defeated these for the simple ability to de-cock if needed. Plus, the real safty is between the ears.
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I've wondered about removing it. I always keep my hand on the cocking lever when my other hand is loading. Like this (Figure 3 on page 4):
http://www.partsmadeeasy.com/manuals/4110%20Air%20Pellet%20Rifle%20A1.pdf
Is that the safest way?
To remove it, just remove the screw, the spring retainer and the "sliding bar"? Anything else to remove, replace, or plug?
Thanks.
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Here's where I started with the Crosman Premier Pointed, pre-tune:
Average fps: 553
SD: 4.5
Post-tune, 1/8" of spacers (washers) on the spring guide:
Average fps: 577
SD: 5.8
Post-tune, 1/8" of spacers on the spring guide and 1/8" of spacers in the piston:
Average fps: 586
SD: 4.8
blah, blah, blah. . . .
Post-tune, 1/2" of spacers on the spring guide:
Average fps: 592
SD: 3.8
At 9/16" of spacers, the rifle would not cock. These numbers seem to indicate a linear progression. From what I have been reading, I believe that I have max'd out this rifle with this spring. I'm gonna soak the leather seal in silicone oil/neatsfoot oil until the new qf2 spring comes in.
Is there any other suggestions?
Thanks again to everyone for all the help! Maybe I'll crack open the Gamo 850 this weekend!!!
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Awesome Henry!!! That's what I call "collecting data" and positive progress!!!
And now its right here for people in the future to see. We can see that spacing of the spring causes a velocity increase. Also, as the spring gets more spacing, the standard deviation goes down, meaning that it becomes more consistent. In the end, everything you've done has got you a40fps gain in velocity , andbetter consistency than what you started out with. Thats why its so fun to tinker!!! It sometimes pays off really well.
I can hardly wait to see the results of your seal soak and new QF2 spring. I think you are definately headed into 600fps territory, and hopefully 700 plus.
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Had some spare time today before the playoff games so I reassembled the B3 with all the spacing in the piston instead of on the spring guide. I had been soaking the leather seal in neatsfoot oil and silicone shock oil since my last post. I was shooting some rounds through the chrony and was surprised to see numbers in the mid 600s. Then, out of nowhere, I got an unusually load crack from the gun and a chrony reading of 853!!! I tried again and everything was back to "normal" in the mid 600s. I shot 10 rounds through the chrony, then 75 pellets trying to clear any lube that may have remained in the seal. I chronied 30 rounds, but deleted the "unusual" sounding rounds from the string that resulted in a decrease of fps in the 400-530 fps range.
I ended up with these numbers:
Average fps: 649
SD: 8.3
This indicates an increase in fps by 100 from stock!!! I also thought the gun's "thud" was louder than usual. So, I moved the spacing to the spring guide again. Here's the numbers after that:
Average fps: 639
SD: 9.0
It would appear that the soaking of the leather seal has made a big difference in the ability of this air rifle. But, is there something this novice is not seeing in this data? I am assuming that the louder crack that I heard (resulting in an fps of 853) is a detonation. And the "unusual" sounding rounds that resulted in a decrease in fps is dieseling?
Should I clean the seal of all lube, or shoot until things settle down?
I'm pretty excited about seeing mid 600 numbers with the stock spring!!!
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That crack was detonation. Seeing a little smoke without the crack is dieseling. A little oil burned off during the firing cycle turned your air gun into a firearm for that shot. If one was all you got, I would not mess with the leather seal. If you get shot after shot like that, it may be a little too drippy with oil. That could cause your spring to crack/break, and IF you had the synthetic seal it would be slowly eating it away. The leather seems to withstand it better. Habit forming, isn’t it?
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Only one loud crack (with the increase in velocity). The dieseling is happening about every 15 shots or so. Will this go away, or should I try to get some of the lube off the leather seal?
So, obviously, detonation is the burning of the lube in the chamber, causing higher pressures. What is happening during dieseling?
Thanks,
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Most likely not. Diesling is a lighter version of detonation, and most high power springers will do it to some degree even with a synthetic seal. Some may not think so because the smoke is so faint, but they do. A leather seal will almost always have some diesling. Nature of the beast. Unless it was so dry as to not be worth its salt as a seal. Naw, if it isn't making that crack, don't wory to much. It will tone down. But even when you get to the point where the smoke may be so faint that you can't see it, you'll probably still smell the frying bacon odor these things are known for, confirming it's still buring that oil. Speaking of oil, toss what you get in that QF2 kit if you get it one, worthless stuff.
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John,
Thanks for the info. I have always smelled that "smell" so I guess I have just made improvements in the piston seal, accounting for the increase in velocity. Lesson learned! Is it reasonable to believe that replacing the breach seal helped by about 50 fps and the thorough soaking of the piston seal, another 50 fps?
I've heard more than once to can that oil in the kit. I've had to order another kit from Steve Archer because South Summit was out of stock (not to mention the probs with their server). Any idea what the average improvement in fps is with the new spring?
Thanks again.
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I got the qf2 kit with new spring today and started over with the cleaning and lubing. Put some serious sandpaper to the new spring, lubed it up, and installed it into a newly lubed B3. It was a real bear to install because the new spring was 1 3/8" longer than the old spring. My first shot was a shocker!! 932 fps!!! No loud crack, but a different sound from the gun. Fired it two more times and got 853 fps and 811 fps. Decided to dis-assemble the gun and check things out. All looked normal, but I decided to squeeze as much lube as possible out of the leather seal. Reassembled and fired several rounds. Had smoke pouring out of both ends of the barrel for awhile, but gradually got better. Things seemed more normal, though the new spring made an obvious difference in the gun. Here's the last 50 rounds:
1 11 21 31 41
791 695 696 686 749
701 716 744 678 721
772 690 682 680 728
813 692 691 731 697
700 695 680 683 729
829 697 680 680 663
701 690 689 679 722
703 688 683 684 694
694 684 675 684 662
809 683 684 679 698
Does all this sound normal? Looks like it was settling down to around 680 fps. I noticed that if I took a little longer loading the pellet, I would get a higher fps from that pellet.
Hopefully, all this is normal and I can expect this gun to settle soon. This weekend I hope to shoot her some more at some paper to see what she can do.
Any help or comments appreciated. A special thanks to my two smaller data collectors, Jacob and Sam!!
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I think that looks pretty much just like mine did after I soaked the seal and used the QF2 spring. A lot of inconsistency because the fuel is not regulated yet, so you get some wild numbers, a few detonations, and heavy dieseling. It just takes a while for all the smoke to clear...each rifle is different. A little smoke will always be there, but you may not notice it. When the velocity and consistency becomes more stable...then you are there. It just takes a lot of shooting. I wonder if you kept your spacing in the spring. If not, it would probably be great to try that again, and that leather seal expansion mod. Once she's settled down, you might still be able to squeeze a little more out of her.(http://../jscripts/tiny_mce/plugins/emotions/images/smiley-smile.gif)
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Yup, right up there. Now look around and see how much it would cost to buy a new gun with those #'s advertised right from the start. Plus, odds are they would not do what was promised either. Now for the good news, That spring was far harder to put in then a replacement Gamo Big Cat spring. And the overall design is both cruder and more difficult to, so if you ever get a Cat, it will be a breeze. Same with many others to. The RS-2 has the need for an adapter for the spring compressor, but even it is basically the same.
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Dave,
I have not tried to space the spring yet. It was a bear to get that thing in there, and my first attempt at a spring compressor is dying a slow death. Don't want to risk to much pressure just yet. I have some oak blocks in the works for my second attempt at a spring compressor.
Nonetheless, I walked around the backyard today and fired about 50 rounds at just about anything that has no worth! Fun, but I was really just trying to shoot the rifle as much as possible. I'll probably chrony some more rounds tomorrow after church.
Thanks for all your help and input on this project! I have a few scope mounts and a compact scope on the way and I can't wait to get this thing together with all the parts and see how she holds a group.
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John,
Amen!! Not to mention the testosterone one generates disassembling and reassembling a gun! Endless worth!
I have a Gamo 850 and that will be my next project. And I am still looking hard at that RS2. I fondled one at Wal-Mart the other day, and at that price, one will be part of my future!
New scope and mounts on the way!
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Your Welcome...one thing that I forgot tomention was that after you get the QF2 spring in there and actually cock the B3, the spring takes a "set" and actually gets shorter than it was when it was new and unset. The forces that you felt when you installed the QF2 spring are quite powerful...and one can easily see why everyone warns of the risk of injury. The good news is that now that the spring has set, it will be a little easier to get out/in...but still dangerous. So I'm glad that you don't want to take any chances about your spring compressor breaking on you. I bought one of those cool B-Square compressors that used to be available a few years ago...its built like a tank...but it was expensive. At first I used a pipe clamp type spring compressor, but that didn't feel right to me, so I jumped for the B-square. Sounds like you have a good design for your compressor, because you have no injuries...now you just need to make it a little stronger. I'm going to take a picture of my B-Square to stimulate the creative juices...maybe you'll see something that you can incorporate into your own compressor. Look for that pic in a little while in this thread.
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In all its splendor
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I'm glad I read through this post. I got my 97 taken down and waiting on lube to get here to put it back together. Looks like I'll be hunting me up some washers for the bearing and the spring ends. And soaking the leather seal.
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After installing the new qf2 spring, it didn't take long to realize that something was wrong inside the b3. I tried to cock it after about 120 shots, and something was grinding.
I took it apart to find that the oilite bearing that I had placed over the rounded end of the original spring guide had broken into three pieces. Probably not a surprise, as it was unsupported around its perimeter. However, the oilite bearing in the pistion was in perfect condition with no wear at all.
So far, I would say that the oilite bearings will hold up fine, if they are laying flat and completed supported. My guess is that if I had placed a couple stainless or carbon steel washers under the oilite bearing on the spring guide, it would have held up fine.
Nonetheless, my new spring guide will fix the problem of the round end on the original spring guide, so this will be a non-issue. I'll continue check the oilite bearing in the piston for wear each time I disassemble the rifle (which is about 3-4 times a day!!!).
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Yep, sounds like those bronzies need support. They are being subjected to incredible forces inside of there, and then the stronger QF2 spring did that one bronzie in. Hopefully they will hold up with more support. It will be interesting when you start with the spacing experiments to see if they still hold up. LOL we always end up at whats the worst that could happen?(http://../jscripts/tiny_mce/plugins/emotions/images/smiley-smile.gif)
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Thanks to a friend and Kev (mcmi), I was able to replace the factory spring guide with a new aluminum one that also incorporates the cover, eliminating that ugly plastic cap.
I also bought a clevis pin and was able to grind the head thin enough to use as the main spring pin. There was excess room around the action, so I didn't have to break out the dremel for any stock work.
With the qf2 spring and the new spring guide, I am still averaging just under 700 fps. I took all the sites off, so I can't see just how accurate it is yet. I've got a Leapers compact scope and one piece offset mount here, just need to find some time!
Thanks again to mcmi and davee1 for the ideas to help me solve some of the problems with this old gun.
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Looking good :) keep us updated, we all like to hear how the B's are doing. :) Ed
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This looks sweet. You did a nice job on the aluminum spring guide. It looks like a really nice fit. Keep us posted, brother.
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Has anyone punched any holes in the B3s for scope stops. I thought about mounting the scope the way I want it, then using the mounts existing scope stop pins to mark where holes should be.
Any advise? Should I drill all the way through, or how deep?
Thanks, as always!
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That looks fantastic Henry!!!(http://../jscripts/tiny_mce/plugins/emotions/images/smiley-smile.gif)
About those scope stop holes...I've been pondering the very same thing. I think the most solid way is to drill and threada hole or holes all the way through into the spring guide. This would allow a metal piece of some kind to act as a scopestop. Of course this would all be behind the moving parts and spring of the B3. So you would have a metal piece with holes drilled in it, aligning with the holes going all the way into the spring guide, and then screws going thru the metal piece into the threaded holes. Thread the holes into the spring guide with 10-32 or so, something easy, readily available, and beefy enough to act as a scopestop. Thats the way I'm gonna do it when I get around to it...in the mean time I'm using the open sights.
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hyounker - 2/1/2009 2:39 PM
Has anyone punched any holes in the B3s for scope stops. I thought about mounting the scope the way I want it, then using the mounts existing scope stop pins to mark where holes should be.
Any advise? Should I drill all the way through, or how deep?
Thanks, as always!
Get the scope set up where you want it and use a transfer punch to locate the spot you want to drill. A transfer punch of the right size will fit perfectly into the hole provided for the set screw and allow you to perfectly transfer it's center location onto the rail.
I just drilled mine right through and cleaned the inside up with a file.