GTA
PCP - HPA - C02 Gate => PCP DarkSiders Forum => : scottinharwood September 05, 2008, 10:42:20 AM
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Well I am going to do it. Tropical Storm Hannah is coming up the coast and it looks like no work outside tomorrow (Saturday).
What to do?
I know, I am going to follow all of the blurbs and great info on this site and start to mod my stock B-51.
I have the new lower-strength springs from McMaster-Carr. Ordered them yesterday, got them today, standard post - its a sign I tell you, a sign!
My goals for tomorrow, shoot some strings at 2700#, 2300#, 2000# and 1700# to baseline the gun with Crosman Premier Heavies.
Then, replace the hammer spring and polish and lube the hammer weight and trigger assemblies then shoot some more strings.
That will probably take my day. Later I may try the mod to make the hammer pin protrusion length variable. One step at a time though. I would really like to be able to fire off a string of 30 to 40 CP Heavies starting with a 2300# fill. The Benjamin Discovery I have has made me well aware of just how breath-taking going to a 2800-3000# fill can be.
Its not going to be sunny out so I will have to rig up some lights over my Chrony
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My Big Ed tuned B51 has the McMaster Carr spring and shoots its best from a 1700psi fill. If I filled it to 2300psi it wouldn't even shoot because the valve would lock. Just something to think about when you start shooting strings with the new spring, better to start with a low fill pressure then increase till you get the curve you want. No fun filling it up just to find out it wont shoot and having to dump air and start over.
If you DO overfill with the lighter hammer spring then you can easily dump some of the air. Here's how I do it:
1) Connect hose to pump/bottle
2) start adding pressure VERY slowly until you hear the pin valve in the fill nipple open
3) slowly, slowly, slowly open the bleeder on your fill rig and slowly let air out. Of course close the valve on your tank first if using a tank rather than pump. If you open your bleeder slow enough the pin/check valve in the fill nipple wont close and you can slowly dump air till you get to the correct pressure. I've used this technique on both of my BAM's and it worked great.
Good luck and happy modding!
Oh yea, do you have a copy of "The Book"?
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Hi Dan,
Yes, I printed 'The Book', that is why I am going to attempt all of this. I was hoping to send it to BigEd for a full work up but no replys to my last couple e-mails. I figure he is really busy or taking some needed time off. I believe he was going to do some work ups on both a 0.177 and a 0.22 Discovery.
Good to know on the starting fill pressure though. I will work my way up from 1000# and see where it locks
So here I go tomorrow, as soon as I rig some lights for my Chrony.
Scott
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Mine goes from 1700psi down to 1200psi with 34 shots in between. This is a .177 shooting Crosman heavies 10.5 grain between 850 to 875 then back to 850 for a nice curve. Ed is taking a 2 1/2 week break to catch up on backlog and also to prep his gun for the Nationals. He posted on the Chinese Yellow forum a couple days ago to mention that he'd be closed during that time. His tune is really worth it, trust me I've owned both an untuned B50 and a Big Ed B51. Ed claims that most of what he does is in "The Book", but there is some magic in there somewhere too:) The only thing I've done to my B51 since I got it from Ed was to rebend the trigger and make a custom cocking knob:
(http://i92.photobucket.com/albums/l16/DanoInTx/IMAG0001-13.jpg)
(http://i92.photobucket.com/albums/l16/DanoInTx/IMAG0003-11.jpg)
They sure are fun guns to mess with for the price. Have fun!
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Dano,
That post came in a 2:16AM EST, its past midnight for you - get some sleep man.
Thanks for the info on Big Ed. I was hoping to get a barrel, de-pinger and other stuf from him, if possible, I will see if he can do the work too. I will still do the main spring change, thats easy. Might even to the power adjuster screw mod too, depends on time and my ability to chrony today. I really like the idea of a lower fill pressure!
I really like your cocking lever knob. As you can see from the picure, my B-51 is older than yours so one thing that would be nice to do is to replace the whole bolt knob assembly with a prettier and better feeling one.
How are you flattening your trigger? I would be afraid of breaking it. I was thinking of making a wood overlay that would reduce the curvature and widen it a bit. Could do it with PVC pipe bit too I guess. Either way, I will polish and lube every thing. I have a Maccari spring kit for my RWS 54, in it he includes Tar, White Grease, and lots of Moly.
I will keep all posted on shot strings and mods I do - this is going to be fun.
Looks like a lot of rain and wind today. We are in HArwood MD, east of DC by about 30 miles so we should get some of the heaviest rains. Gutters are clean so it should be OK.
Scott
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To bend the trigger without it breaking you need to anneal it between bends. First I straightened it out, then I reshaped it using a piece of round stock and a ball peen hammer....like an old school blacksmith. To anneal the trigger I used a propane torch to heat it up to a dull red color then let it air cool, I've heard you can also quench it in water, but air cooling worked fine for me. Brass is pretty easy to work with, just go slow and anneal between any heavy bending....I think you can get a replacement trigger from Best Airgun for about $5 if you break it, or so I have been told. The biggest problem with the B51 trigger blade is the "hook" and how far forward it's set. I removed the hook and also moved the reach back quite a bit. They polish up pretty nice when you're all done. I made the bolt handle on the lathe and then bent it the same way as the trigger.
Good luck and enjoy your tinkering.
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Ok here is what I did:
Disasembled the B-51.
Found the breech block screws to not be too tight. When I removed the breech screws I found that the top transfer port o-ring had about 25% missing - a bigchunck of the diameter just gone and I never suspected it.
The bottom transfer port o-ring was shot too, had the funny middle spit that bad o-rings get. So I replaced them both.
Second, the trigger assembly components were really rough, as though they were machined quickly then slaped in with out polish. I burnished the contacting surfaces with a diamond hone than polished the same surfaces with oiled 1000 grit wet-dry sand paper. I used a white greese to lube the rub and pivot points. The action is now very smooth and light now and because of this I no longer seem to mind the trigger shape.
The hammer and hammer spring guide were in the same shape, rough. I chucked them into my wood lathe and polished them first with 600 grit then 1000 grit sand oiled sandpaper. Now the hammer moves back and fourth with vey little friction.
I polished the bolt and lubed it with white greese. Replaced the probe o-ring too.
I cleaned and oiled everything.
I replaced the main spring with the McMaster Carr spring. Boy can you tell the difference before you even put them into the gun.
Slapped this thing toghether, filled it to 2000# and it was locked.
Bled it to 1750 # and I was shooting in the high 100's
I kept shooting and at about 1600# velocities jumped to about 700.
I think I will try the power adjust mod with the olds spring. Or I will put a 1/2" spacer on the spring guide to tighten up the new M-C spring a bit.
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Try increasing the spacing between the pin valve and the hammer before shimming the spring, leave just a little bit of the hammer screw poking out the front of the hammer and see if the FPS comes up, maybe 1/16". If that doesn't work add washers one at a time until you get to desired power. Mine gets about 17fpe with Crosman heavies at 1500psi.
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I thought about putting a weaker valve spring in the valve. Any thoughts on that?
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Hi Jaymo:
The McMaster Carr spring shown in 'The Book' is a much weaker mainspring. I decided not to futz with the main pressure reseviour spring at all. I do not think you need to either.
I went back into the cave and continued my tweaking (I am an electrical engineer so the term is appropriate for me). I turned down the hammer striker screw until only a little bit was showing, maybe 1/10 of an inch or less.
Knowing I wanted a main spring tension some where between the stock BAM B-51 spring and the McMaster Carr spring, I stacked 3 size -111 o-rings on the spring guide to take up about 1/2" more ofr spring space (added tension). I put it all back together and charged the gun to 1950#.
My shot strings started at the low 600's - not too good but I decied to fire to see if the gun would hit 875fps.
It took a few shots but I finally hit 877fps. I then used my Hill pump and pumped until I read the reseviour pressure; it was 1700#.
I continued to fire, my next thirty shots started at 906.8, slowly crept up to 931.9, then crept down to 899.
Thats thirty shots with an average of 915 fps and a standard deviation of 6 to 7 fps. The ES was under 20.
I think I have hit my sweet spot on this tune. I will continue to fire it and see.
Again, I shoot lubricated Crosman Premeir Heavies (10.5gr).
I am happy so far and the tune cost me about $20.
Scott in Harwood
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Sounds good Scott! Not so sure about using o-rings for spring spacers though, springs like to rotate when they are released and might start to shred your o-rings giving really odd FPS numbers. I'd stick with polished steel washers if possible, but what do I know:) Might get a slightly flatter curve with a little loss of FPS by shimming just a tad less than you have, but I guess it depends on what sort of power you're going for. Using steel washers instead of the o-rings might add a little bit of mass to the hammer also, giving you a bit more smack on the valve stem. These guns are fun aren't they?
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Hey Dano:
All those thoughts went through my head, but the o-rings were right there in front of me and I would have had to really scrounge for hours to get correct sized steel washers; my mantra in my basement shop is 'I know its in here somewhere....' and then three or so hours later I got to Home Depot anyway. The hammer spring guide and inside of the hammer are n0ow polished to a bright shine and lightly lubricated so there is plenty of rotational capability on at least that end but I will just have to fire a bunch of pellets through it to see the effects - oh darn ;)
I found something out about my Beta Chrony in all this. If I do not accurately place the muzzle of the rifle at both the same distance (that I knew) and also at the same angle, it can throw off the readings. In that nice 30-shot low 900fps or so string, I had two, widely seperated low 800 value shots. I was disapointed after the first one, thought hte tune did not take. On the second one I noticed that I had canted the barrel up a bit and angled it from side to side over the chrony. I really think those two shots out of 32 were bad data points so I did not include them. I watched my angles and distances in the last 15 shots and they all came out low 900's where I wanted them.
Live and learn I guess. I have never run so many pellets over the chrony before.
Oh yeah, read all the warnings took lots of precautions, go the safety ball bearing and srping off OK, put it back together and had to rotate the safety plate and sproing! there went the ball bearing and spring. So I am safety-less now, but I never used the safety before anyway so no big loss.
I am going to run a careful set of chrony numbers today sometime and post before and after data.
Scott
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When I initially put the gun back together, I reinstalled the dreaded screw #26. It locked the hammer. I turned it a bit in then out a bit to reorient the screw head and depth, finally got the hammer to move but not nearly as cleanly as without the screw. Sooooo, screw 26 is no-more in my B-51. So far, I am not missing it at all!
Now, I finally hear a ping when I shoot. What is it from? and where does a de-pinger go. I saw some pics in 'the book' and could not figure that out.
Thanks
Scott
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A de-pinger is basically a baffle that goes in the air tube.
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Well:
Sat down and ran more shots over the chrony, carefully. Those odd ball low 800's readings that I got two of in a string of 32 nice 900+ shots turned out to be real.
I shot 50 more over the chrony and I keep getting the occasional low velocity shot, sometimes two in a row. I raised the fill pressure from 1700 to 1800 and noted the same thing.
Then I put the scope back on, three shots to zero it - sort of - then began shooting 5 to 10 pellet strings at targets. I am set up on sand bags so my gun is steady as a rock. The groups open as you would expect with a steady lowering FPS. However, there are some shots that just show that the velocity has dropped for that shot.
So its back to the drawing board. I am thinking of trying to shorten the stock spring in increments. Who out there has or sells a replacement stock spring for B-50/51's. I always need to be able to get back to where I started from.
Thanks
Scott
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Hey, Scott, what are you shooting for pellets? Reason I ask, I get the same thing with Crosman Premiers, and I know damn well it's pellet variation. Even with the Premiers in the box, you'll get a (un)fair number of under or over sized pellets. So if you're shooting Premiers, try something else, maybe JSB Exacts or Kodiak/Barracuda Match. My B50 (that Dan originally owned) liked the Premier Heavies, and did the same thing. Nice write up, BTW, and good luck.
Dave
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Thanks Dave, I will try some of my others, I have collected quite a few types ver the years, but keep seeming to come back to CPH's
I have some JSB Exacts, and some RWS plus others.
My AA S400 E loves the CPH's.
I will let you all know.
Scott
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in fps might be due to, lube on the hammer (run it DRY), your rubber shims if that's what you are still using, VACCUM behind the hammer if the safety screw is still there, the sear spring being to strong (factory), and naturally, other...... .
I have the one in the "BOOK" with the 2mm shortened hammer, works really nice, 2000psi fill when stricker screw is set flush w/Mc spring and a shim in the END CAP which avoids adding hammer weight (shim must be hollow in the center for the spring guide to clear. Skip screw #52 (?) as it seems you have. Use a cut Bic pen spring for the sear/trigger springs, elimineates drag and allows a 7 ounce pull, new trigger blades are indeed $5.00 from Xisico, they would be happy to sell you another stock hammer spring (and/or just aboput any part you might want) cheap and fast. The stock barrels are really good if re-crowned and cost maybe $60.00 for a reciever/barrel unit. Dont change/mess with the valve/striker return spring unless you need a TON of power with a very low shot count. Also check the brass retaining nut and o-ring on the valve stem (relates to low fps spikes) sometimes it just does that when the air hits that o-ring just right. A better idea is to thread a peice of delron and replace that brass retainer AND o-ring with that.
Looks like you have done a pretty nice job of tuning it up yourself, a great airgun to learn on.
And as it seemed you had a pic of two airguns there somewhere I though I would post ours again,
(http://i23.photobucket.com/albums/b385/spysir/BamAA410004.jpg) (http://s23.photobucket.com/albums/b385/spysir/?action=view¤t=BamAA410004.jpg)
Keep us posted on your finishing touch's.
John
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Thank you John, I really appreciate the info and those are some way-cool looking guns. I am running the hammer wet, I will dry it out.
Not sure about the statement you made: "Also check the brass retaining nut and o-ring on the valve stem (relates to low fps spikes) sometimes it just does that when the air hits that o-ring just right. A better idea is to thread a peice of delron and replace that brass retainer AND o-ring with that."
Are you talking about the retainer and o-ring for the valve stem that the hammer strikes against to release the puff of air?
I shot 9 5-shot strings on the attached picture. Started on lower left target to zero, then went left to right and up. The upper left shot pattern is with my AA S400 EX using the same JSP Exact pellets (per the last poster's suggestions of moving off of the CPH's). From that I am pretty sure I understand the sight picture and have my hold correct.
I have some close up photos of the crown, its a rough looking grind so I am sure that may account for the flyers you see in the pics; the AA S400 single-holed all five. I have a couple of e-mails into BigEd one of which includes my thought about replacing the barrel with a 25" LW. But only if I can get the FPS pretty constant for a given pressure range.
All shot were from 12.5m (my basement, table saw to wall distance), pellets lubed with FP-10.
Any idea of what the weight of the JSB Exacts are, looks like the same can that is in your photo.
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Whoops, here is the correct picture
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I use a rest when I shoot over my chrony, it's the only way to make sure it's the same every time. When you shoot at a slight angle you are in fact changing the distance the pellet has to travel between the sensors. The slight angle might not seem like much, but when you are measure FPS within a space that's only maybe a foot and a half it's easy to scew the results from inaccurate rifle positioning. See pic:
(http://www.gatewaytoairguns.com/airguns/photos/get-photo.asp?photoid=650)
As for the inconsistancy I agree completely with John(Spysir) below. John was fiddling with these before I knew what they were.....he actually mailed me my first Mcmaster Carr spring:)
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"Are you talking about the retainer and o-ring for the valve stem that the hammer strikes against to release the puff of air?" It is a problem spot, just not a great design.
Here is a graph from ChrisK just to show what a Bam will do:
(http://i23.photobucket.com/albums/b385/spysir/Shotstring121507.jpg) (http://s23.photobucket.com/albums/b385/spysir/?action=view¤t=Shotstring121507.jpg)
And a target with a long LW barrel, all five shot groups off a 2000psi fill at 30 yards:
(http://i23.photobucket.com/albums/b385/spysir/lotharbamtarget.jpg) (http://s23.photobucket.com/albums/b385/spysir/?action=view¤t=lotharbamtarget.jpg)
But what really impressed me is the groups a stock cut and crowned Bam barrel makes, I have in my mind Dan might have a picture of some of those?
John
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spysir - 9/7/2008 11:51 AM
.........But what really impressed me is the groups a stock cut and crowned Bam barrel makes, I have in my mind Dan might have a picture of some of those?
I quit shooting mine, it was a waste of targets. Now if I could find targets that were as big as a thumbtac head, then maybe I'd shoot it more, but right now it only makes one tiny .177 hole and that is just no fun:)
Big Ed said that my recrowned stock barrel was good enough where I wouldn't see any improvement by buying an LW to replace it, I tend to agree.
Here's a 34 shot string from a 1700 psi fill.... I refilled at 1200psi. I was shooting CP Heavies.
(http://www.gatewaytoairguns.com/airguns/photos/get-photo.asp?photoid=1237)
This was when the gun was brand new, I would guess that it has smoothed out a little now that I have some shots through it, but I probably wont chrony it again as I am pretty happy with the results.
Take care,
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Hey Dano,
My chrony plot pretty much just goes down hill. Starting at 1700 to 1000 over 50 shots.
From about 930 to about 850 fps. Have not yet re-opened to dry off the hammer. When I do, I will polish the inside f the hammer tube, I only cleaned it the other day.
Scott
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Ok, here it is, probably the final entry for my B-51 tune up using ‘The Book’.
When last we saw our hero, he was very frustrated in that his shot string had a pretty much straight down-hill slope and there were sporadic (8 shots out of 50) in which the muzzle velocity of the Crosman Premier Heavies (10.5gr) dropped by about 100fps from the general string run of values. Not good said our hero and he sought greater wisdom from the ancients (the Darkside Forum experienced tuner’s).
Our hero received many great and timely comments and suggestions. The wise ancients, DanoInTx NS SpySir bestowed the latest leafs of wisdom on our hero and the result was a shot string that was perfect from our hero’s goal in the B-51 tune up process in the first place.
As you will recall, our hero sought wisdom on the B-51 tune up from the Darkside forum and stumbled upon ‘The Book’ in which much wisdom be many ancients was inscribed. Our hero jumped in, feet first and brain last, and managed to obtain a gun that shot in the mid-600’s fps.
Our hero followed ‘The Book’ in that he dissembled the B-51, dissembled the trigger assembly and hammer spring mechanism and modified or replaced various components. On inspection, our hero found that the cocking bolt mechanism was a bit stiff and gritty feeling. Also, on removing the breech, our hero found that the top transfer port o-ring had about 25% of its ring missing (no bits and pieces laying about, just missing. On inspection of the lower transfer port o-ring, our hero found that this o-ring had a classic failure indication, a concentric split on the inside diameter of the o-ring (a typical failure found in AA S400 breech seal o-rings). Additionally, our hero found that the breech screws were not very tight. Finally the bolt probe o-ring was worn looking.
The first step that our hero took was to clean the barrel and breech since he could run a bore snake all the way through both the barrel and the breech bolt areas at once. Goof-Off on a pad run through 3 or 4 times finally came out clean. Our hero then used a bore mop soaked in bore oil to lube up the gun bore (not the breech).
Our hero then polished the bolt and used white grease from Maccari to put a light coat of lubricant on the bolt. Polishing the bolt was accomplished by lightly sanding with oiled 600-grit wet-dry sand paper followed by oiled 1000-grti sandpaper.
Then came the hammer and hammer striker. Our hero chocked the hammer into his wood lathe and used the same 600-grit and 1000-grit oiled sandpaper to polish the hammer mechanism, paying particular attention to the grooved area of the hammer where the trigger sear must engage and smoothly disengage. Also, our hero polished the spring guide and the inside of the hammer so that the spring guide would turn smoothly in the hammer when the gun was cocked and fired (the spring wants to rotate). Since our hero was replacing the stock hammer spring with a less stiff McMaster Carr spring (ala ‘The Book’) he turned in the hammer striker inward screw so about a millimeter of the striker screw would be exposed. He did this knowing the hammer spring change would give velocities in the 700’s rather than his desired roughly 900 fps. Increase the travel, increase the momentum and hence the strike force on the discharge valve stem and a higher resulting velocity.
Our hero then committed a big mistake; he used a thin coat of white grease lube on the hammer and hammer chamber.
Finally, our hero used a diamond stone and 1000-grit oiled-sandpaper to polish the trigger surfaces that would come into rubbing contact with other trigger or hammer components. Then he used that wonderful white grease to lube all trigger rub and pivot points.
Upon reassembly, our hero tried a fill to 2000# and fired a shot off, the pellet did not even come out of the barrel – oops, I had gas lock due to the low tension McMaster Carr spring. DanoInTx warned me he had had valve lock at 2300 psi on his first try and our hero thought 2000 psi would be low enough – no dice. Additionally, on assembly, our hero was very careful with the safety spring and ball bearing, so careful, he lost them while trying to rotate the safety during reassembly – he should have used the plastic bag method mentioned in ‘The Book’.
Our hero then slowly bled down the reservoir pressure to 1700# and was able to get a pellet to fire out the barrel. Unfortunately, our hero could easily follow the pellet trajectory and watch it arc gracefully up and then down to hit the floor well before the target 12.5m away. Hmmm, maybe I need a little more spring tension (remember that grease on the hammer? Don’t forget it now).
Our hero then opened the breech assembly one more time and decided to add three -111 sized o-rings on the spring guide to pre-tension the spring a bit more. Comments abounded from the wise ancients about the possibility that these o-rings would wear out and that an annular spacer in the breech plug or stacked metal washers on the spring guide might be better – our hero had o-rings, and they were handy.
Upon re-testing the gun, by sound, our hero noticed a definite increase in pellet velocity – oh boy, now we are getting somewhere.
Our hero then charged the gun up to 1900 psi and started firing off pellets over his Beta Chrony. The shot strings, to say the least, were not impressive. The velocities started out in the low 600’s and climbed through 800. Our hero checked the fill pressure on his Hill pump and found it to be about 1700. The shot string looked good initially, but our hero noticed every few shots the velocities would drop by about 100 fps – not good (remember that lube in the hammer chamber?).
Now, our hero starts shooting round after round over his Chrony then realizes he is not being consistent in his angle over the Chrony. He changes and tries to free-hold more consistently but there are still ups and downs in the shot string velocities.
Frustrated, before stopping for the day, our hero dumps a bunch of 3in1 oil into the hammer chanber to reduce friction – so he thought. He fired off one more string of twenty and saw even worse up and down results. Our hero, beaten and bleeding, stops for the day and starts crying for help from the ancients at the Darkside Forum.
SpySir comes to the rescue the following day and tells our hero that lube in the hammer chamber is not a good thing – vacuum can build up behind the moving hammer, slowing it down unpredictably – can our hero get a big Duh-Huh!.
The next day, after our hero has a headache from beating his head against the wall, he opens his B-51 for the 4th time and cleans out the hammer cylinder and polishes it with both oiled 600-grit and 1000-grit sandpaper. He then cleans and dries both the chamber and the hammer assembly and puts on and then polishes off a coat of Molly Paste. Noting that his shots had a high of over 930 fps, our hero then removed one of the three o-rings he placed at the base of the spring guide to put more tension on the hammer spring; thus, he hoped, reducing the shot velocity to a value closer to the proverbial 900 fps he desired.
Our hero then re-assembled his B-51 and in the process replaces, again, the transfer valve o-rings and the bolt o-ring. He noticed that on his last assembly that the breech block did not sit uniformly (side to side) on the pressure chamber – be careful to alternately tighten the two forward screws while insuring that the seam on both sides of the breech is uniform.
Our hero then fills the gun to 1750psi and shoots off one shot – it sounds good and hard. He then sets up sand bags for his B-51 so that the placement of the gun relative to the Chrony will not change from shot to shot (he’s learning!) and he begins shooting and logging his shot strings (again – man this part is boring).
The results are impressive (at least to our un-tutored hero). Our hero wanted a string of consistent shots around 900 fps with 10.5gr Crosman Premier heavies with a fill pressure lower than the breath-taking 2700psi he was using. The shot strings started out at 854 fps gradually went up to 912 fps then gradually down to 859 fps in a 50-shot string, success at last - as follows:
Begin Fill Pressure: 1700
End Fill Pressure: 1100
Shot No. Velocity Shot No. Velocity Shot No. Velocity Shot No. Velocity Shot No. Velocity
1 854.1 11 892.2 21 911.3 31 903.7 41 882.2
2 858.7 12 895.3 22 908.8 32 896.0 42 880.1
3 865.0 13 896.3 23 912.4 33 898.5 43 875.9
4 876.2 14 904.0 24 908.0 34 898.5 44 877.5
5 869.0 15 901.4 25 908.9 35 896.3 45 868.9
6 882.4 16 907.6 26 907.6 36 892.8 46 870.3
7 879.4 17 903.4 27 909.3 37 896.2 47 866.4
8 879.4 18 907.2 28 907.6 38 891.4 48 867.4
9 881.5 19 906.8 29 905.5 39 889.4 49 858.9
10 890.0 20 910.1 30 905.1 40 884.0 50 859.6
Hi 890.0 Hi 910.1 Hi 912.4 Hi 903.7 Hi 882.2
Lo 854.1 Lo 892.2 Lo 905.1 Lo 884.0 Lo 858.9
Ave 873.6 Ave 902.4 Ave 908.5 Ave 894.7 Ave 870.7
Es 35.9 Es 17.9 Es 7.3 Es 19.7 Es 23.3
Sd 11.5 Sd 6.0 Sd 2.3 Sd 5.5 Sd 8.1
Our hero thinks that now he has an easy-pumping gun that requires only a 1700psi fill for 40 good, moderately high power shots.
Now, on a serious note, my thanks to all those at the Darkside Forum that gave such good support and provided such great inputs and suggestions. I am happy where I am at on this tune. Now, I think I do need a barrel re-crown to get close to the AA S400 one-hole strings that I can get on a good day.
Special thanks to:
Dan (DanoInTx) and John (SpySir) – this forum is the greatest!
Scott in Harwood (our hero).
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Scott persistence is a good trait to have and I am glad you won the battle . But do not forget the lesson about lube on the hammer when you get started on the Discovery . I have tried it and unless it is a super light smear of white lube or dry lube it will cause hammer drag as well. I have followed many unhappy Discovery owners stores about velocity drop after doing a trigger mod but most of them have caused this pour performance them selves by lubing the hammer . Marvin
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Ohh, Marvin you must omniscient, I was just thinging of doing my Discovery. I already did the lower link mod on it and I have an e-mail request into BigEd for the super sear, HDD and power adjuster set up.
I will remember, no lube or, as I did here (finally) a coat of molly then wipe it off for some minimal corrosion protection.
I think I am addicted to the Darkside now (cue the scarey music in the background).
Scott
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Boy, I can tell I was tired when I wrote that one, lots of typo's and english problems.
Sorry all.
Scott
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N/T
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Looks like you win!
Glad I could help:)
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You rock man, thanks again.
Checked out your album - cool pieces, cute kid, great wife - what more could you ask for!
Scott
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Just how extreme are you talking about? The reason I ask is because I want to shoot 28 grain Eun Jins or maybe Crow Mags as fast as I can without sacrificing good hunting accuracy. I want to make a bunny and beaver slayer out of mine. Bear in mind,I'm not trying to be a smart@ss. I just want to know what velocities I can achieve with my .22 B50 and heavy pellets. If I could get 900 fps with Eun Jins, I think I'd be happy.
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What about spray moly or graphite dry lube? would a thin layer of one of those be OK, or would it cause valve lock, also?
I'm thinking I need to buy a spare barreled receiver, bolt, ans springs. I'd like to make a .30 caliber B50.