GTA
General Discussion To Gateway To Airguns => The Shop => : fnash February 16, 2008, 02:03:42 PM
-
Just received my MP 512M and noticed that the barrel ID is large in that the pellets just fall in and sometimes go below the opening edge. If the skirt of the pellet swells out and seals it is ok, but do they swell out that much? I also took a pellet and pushed it through the barrel with a cleaning rod and notice that there were loose spots along the way. Tight, loose, tight, loose so to speak.. I was using RWS pellets and they are fairly large on the skirt.. Maybe a pellet with a large skirt would shoot better in this rifle.. but which pellet has the largest skirt? Any help on this? It shoot pretty good but it is harsh.. It only shoot in the 500's but is still hard to keep the scope in place. I will have to get a mount with a stop screw. There are two indents on the rail for that purpose. It is pretty powerful for it's weight, 7 pounds. Seems like a toy compared to my heavier rifles but sure has a punch... FN
-
Frank, did you try another brand of pellet. Maybe you got a bad lot of pellets. Generally the RWS Superdomes fit snug in all my air rifles. The pellet really should not fall past the breach hole. And the pellet should have some uniform resistance from one end of barrel to the other. Only exception would be a barrel that was choked.
Gene
-
I will try the Superdomes right now. I don't know which one i used. I will try each of them. Back later...Fn
-
Tried all my RWS pellets, the Beeman Ram Jet and Gamo Hunter. The all go through about the same. The pellet will fall a little better than a sixteenth beyond the breach hole. When I push it with a cleaning rod it is snug at first when pushing from the breach end. Will be almost free ( can feel a slight drag) until it gets to the muzzle where if feels like it is choked down some.. I have not tried this with my other guns as they do not have the loose pellet fit.... FN
-
Hi I got a mp 512m too mine was a little harsh till I did a tune it is an easy rifle to take apart it didn't need a compresser to take it down just cleaning the power plant and polishing the trigger sear helps a lot I've kep mine with iron sights and I had to put a spacer in the barrel pivot it was loose and was not able to get tight enough I used a pellet can top it was a good fit that helped a lot I only have the daisy wadcutters I don't mind wadcutters but daisy pellets are not made very good lots of bent skirts but at 10yds with iron sights i am able to keep 5 pellets in a 3/4" bull not tight some touching but it's not easy seeing the bull good at that distance, my eyes are not \as good as when I was younger. I just turned 70 last week and I still scuba dive. I built a new wood stock for the 512 it added some stability to the rifle about 1 lb. more in weight but I think it's the solid feel that you get with wood over plastic.It's a nice fun gun to shoot and a keeper. I hope you like yours as much as I like my mp512m it just feels right.
-
Hi Howie. You did not mention if the barrel ID was a bit larger than most other rifles. The pellets in mine fit a bit loose near the end of the breach, but pushed just a little they tighten and then the muzzle feels a bit choked... Which is alright too.. I have not taken mine apart but looks like by removing the pin the trigger and all come right out. My trigger seems to be fine, just that the trigger blade itself is not rounded and the square edges seems sharp after shooting awhile. Am I right on that in that the trigger comes out along with the end piece?? I would like to have a look see of the cylinder and what is inside, maybe hone it a bit... and tar the spring... can you advise on that some,,, thanks....FN
-
Hello Frank,
If you intend on going into your springer air rifle, I would strongly recommend using a spring compressor, it may not seem necessary at this time, but the eyes you save may be your own. Even though you may not feel the need for one, a loose spring can be very painful and dangerous !
I don't want our family members hurt !
Bill
-
Thanks for the warning Bill, and it is wise to use a compressor... I do have one and use it on any rifle I work on.. I would not take that chance.. Besides if you don't get hurt, things will fly all over the place and will never be found, won't even know what the heck the part was....... Thanks Again.... FN
-
I have a spring compresser but when takeing it apart I found the spring pressure was not very hard, the instructions that came with the rifle didn't say antthin about needing a compresser, also when puching a pellet throught the barrel it had some choke at the end as it should. the sear can be removed by slipping the pin that holds out enought to get the sear out without takeing the hole trigger asse. appart. you will need a rag to put oner the trigger unit then takeing the power plant appare if you look at the assembley you will see thet after removing the pin at the end of the popwer plant the trigger unit needs to be turned to releace the sprin not much and the spring is not under a lot of pressure a rag will help keeping your hand from hurting when appling pressure. you can use a spring compresser if you want to but I don't thing in this rifle it is needed.
-
Hi Howie, being as you said it was so easy I took my 512 apart today to tune it. I think I found out why it was so harsh. The piston just fell out as the seal was undersize to the piston. It has been slamming. I could not figure why a low power rifle would almost knock the scope off the rifle. The seal measured .975" and the piston measures .978". I could see an imprint of the bottom of the cylinder in the seal. Now I have to find a seal. Wanted to send Jim Maccari an email today to see if he can help me but seems his web site is shut down today, maybe for the weekend.... The seal looks just like a synthetic B3 seal but the mushroom it fits over is smaller. Has to fit a .648" top with a .50" groove. And another thing I think a B3 spring would work also. Just a little longer to give it some needed extra push... FN
-
Hi do ypu think you could put something in side the seal befor putting it back in the gun to make it tighter maybe a washer, ect.? something to stretch it out.
-
Good idea,, I will give that a try.. just finished making a shim as you did out of a pellet tin for the barrel pivot.. Maybe I can heat it in some hot water to make it easier to stretch... Will try to cook something up... Thanks Howie..... FN
-
Contacted eaacorp@eaacorp.com about the seal, no response yet. They have a parts list with prices, shows breakdown of rifle which would be very helpful.. FN
-
If you can find some heat shrink it might do the trick otherwise I've used Teflon plumbers tape and wraped the end of the piston before installing the seal. We are talking about 3/100ths right?
P.S. My 512 is coming today!
-
Yes 3/100th.. I have ordered new seal but not arrived as yet. It does shoot in the 500's as is, so am thinking a seal that fits should make a difference.. If yours seem to slam and jolt you may have the same problem. Mine would push the scope off the dovetail.. As stated above.... Sure hope you don't have the problem... I have polished everything while waiting for the seal. Unlike a Chinese spring the ends are not flattened, so had to do that and polish. Also no guide on the rear of the spring ... They do have a nice long guide on the front, steel... It is simple to take apart. You have to turn the trigger assembly slightly counter clockwise after removing the rear pin as it has a notch where a small pin holds everything in place.. When putting back together you have to wiggle the trigger up and down to allow the pin to go in, otherwise it binds up and if you force it you will break or bend the trigger... FN
-
Damit! Mine has the loose fitting piston seal too!
I took it apart and the piston just floated back & forth in the cylinder so I took my finger and covered the exit port and pushed the piston as hard as I could and you know what ? Air came back out the piston cylinder. (Not good)
I took my own advice and wrapped the nipple the seal goes over with plumbers Teflon tape till the seal when reinstalled on the piston produced a little drag. I'm shooting right at 600fps but I honestly think it can do better.
As I said the piston seal had just a little drag and I think it needs a little more if I compare it to the amount of drag I feel from other piston seals when in the gun.
I've fiddled with a few.
My guess is when all is done she'll be a nice shooter. I also think the Russian spring is more than likely better than the Chinese one.
Now to take her back apart and find something thicker than the Plumbers tape??
-
Sorry to hear that Dank.. I have not received my new seal as yet, maybe tomorrow. Will let you know the dimensions on it. Had to order it from EAA down in Florida. If you call them ask for extension 14 not 10... That hard nose guy on 10 would not warranty replace the seal. Maccari said he did not have anything for that rifle. But seems like one of the seals he sells should work but would not know what to order and they are not cheap, with shipping on top of it yet.. Did your rifle slam pretty hard like mine did? I do have mine all tuned waiting for the seal and I too think it will be a nice rifle with everything working right... if it shoots 500 with a by-passing seal what will it do with one that fits... How do the pellets fit in the breach? It seems a bit oversize on mine.... FN
-
Well so much for precision air gun products Dan..:) I just had to say that..:)What size seal is the standard seal? O/D.
Gene
-
I think it is 25 mm, which is just under one inch. The lip would have to be a bit larger than that to fit tight... FN
-
I am pretty sure there is a seal that will work. Or even a work around. Let me check and get back to you guys if you have not already found a remedy.
Gene
-
If you look above at my 2/23/2008 1:45 PM post I give the dimensions... A Chinese seal won't work because the inside of it is to large to fit this piston.... FN
-
Your I/D and O/D are obviously a different measurement. Normally on many air rifles the piston seal is just about 1" or a tad above. Take a look at Mac's web site again and pay close attention to the seal sizes. I think you will realize with a bit of imagination that you will find the right match or close enough. You may have to spin the seal to downsize it but be careful not to get it hot or to rough. The seals that Jim sells are good quality seals and out side of the telsa seas will conform to your cylinder very well.
Gene
-
What concerns me is will the ID of the seal fit tight over that mushroom on the end of the piston.. I have read his instructions for fitting a seal and he does stress to take it slow and easy... FN
-
You have a point. It appears to be a standard size. But I could be looking at it with a crossed eye..? The only way is to have a seal in front of me or you and the piston, with a set of calipers to measure. You want the seal to fit snug on the mushroom end. You generally have to us a bit of lube and force it over the lip with your fingers. The tapper is also generally a standard tapper.
Gene
-
Yes the OD of the seal is standard but don't think the ID is... Was just looking a Maccari's web page and it seems the seals are open in the center. Not solid like this one or the Chinese Seals.. FN
-
It does not have to be solid...:)
Gene
-
EEA shows an exploded view of the 512 only Not the 512M;
http://www.eaacorp.com/diagrams-mp512lg.html
(http://www.eaacorp.com/images/Diagrams/mp512diag.gif)
What I find curious is part #s 45 threw 49 VS. 15 & 16. The 512m obviously has the 15 & 16 in the gun. Those numbers coincide with the ones in my manual. I think a phone call to EAA is needed at this point. Remember phones? some things you can't explain over the web. I could just order both groups butt....I'm curious about 45-9!
Last night I re wrapped the piston table & pedestal with high temp electrical tape then reinstalled the seal and it fit nice and snug in the cylinder. However thank you Gene for bringing to FN's attention "there is no need for the seal top to be solid.
You see by the time I enlarge the pistons table & pedestal enough with tape, the seal develops a cone shape due to the top being solid. Therefore if I don't have enough success with my calls to EAA and possibly Maccari today I will make my closed top seal a ring by removing the top or makeing a large hole so when installed on the now larger table, the top can catch up with the bottom and be the same size...not cone shape.
-
fnash - 3/3/2008 12:13 AM Sorry to hear that Dank.. I have not received my new seal as yet, maybe tomorrow. Will let you know the dimensions on it. Had to order it from EAA down in Florida. If you call them ask for extension 14 not 10... That hard nose guy on 10 would not warranty replace the seal. Maccari said he did not have anything for that rifle. But seems like one of the seals he sells should work but would not know what to order and they are not cheap, with shipping on top of it yet.. Did your rifle slam pretty hard like mine did? I do have mine all tuned waiting for the seal and I too think it will be a nice rifle with everything working right... if it shoots 500 with a by-passing seal what will it do with one that fits... How do the pellets fit in the breach? It seems a bit oversize on mine.... FN
Thanks FN.
Mine was not all that harsh but it was enough to walk the scope.
I'm real curious about the new seal dimensions?
As far as the breach fit it I like to think of it as accommodating rather than over sized. I never find myself fumbling to get a pellet in the gun like I do with many other guns. It seems to be similar to my other Baikal guns. I think the just build the barrel with the breach area a tad larger. I find it has no drawbacks and is in fact quite convenient.
Pleas post your results.
All in all I'm very happy with the company Baikal from their competent owners manual to their unusual designs they seem to have that poor guy in Siberia in mind without a computer or access to the web when the make their guns so easy to take apart, repair and re-assemble. They're usually very original and different designs too.
I'll keep this thread going till we figure this out.
-
Gene_SC - 3/3/2008 12:18 AM
Well so much for precision air gun products Dan..:) I just had to say that..:) What size seal is the standard seal? O/D.
Gene
Ya know Gene,
♥♥♥♥ βÅÏκåι ® I still love-em ! Even if it's with a black heart.
-
You know this is a funny little gun but it shoots fine and accurate It looks a little funny with the drop stock and is very light but it would be great if you were all day hunting with it ,I've kept mine with iron sights and like it fine .At 10 yds it will keep in the black if the black is about 1 1/4 inches dia. howie
-
The phone number is 800-536-4442 Ex 14... The M means it is a .22. The 45 thru 49 looks like it would be a leather seal held in with a screw, where 15 and 16 is the synthetic seal what is what we have.. I gave Maccari the dimensions as above but he did not advise on any of his seals that would fit. Maybe he did not look my message over good. I would just as soon put in his seal as I know it would be a better choice... FN
-
After reading FN's post I e-mailed Jim Maccari and carefully described our situation and seal complete with pic's. He came up with nothing but will think more on it.
EAA finally got back to me and told me the replacement seal is .OD IS .999 ON THE PISTON SEAL.
I had already ordered one along with some other stuff so we'll see after it gets here Sat.
In the mean time I too have all the parts polished up and ready to go.
I'm not holding out much promise since the modified seal I have is also .999 on the piston.
I drilled out a hole in the top or the seal to compensate for the larger diameter piston table & pedestal created by cleaning and dipping in Plasticoat so when I re installed the seal it wouldn't funnel cause the bottom had stretched yet the top couldn't because it was solid.
After I installed it back on the piston I filled it with hi-temp silicone to make it solid again. It brought the fps back to a solid 600.with RWS Hobby's.
This is the first Baikal I've had that didn't shoot the stated FPS out of the box with normal wt. pellets.I'll just have to accept it for what it is and work on making her smooth. I do have a lot of Chi-junk pellets I might pour in the stock with expanding foam for starters.
-
Nice pictures, and looks like a nice job your doing. I ordered a seal from EAA but not received yet. Called them on it. Maybe today or tomorrow... Another thing I noticed is in the breakaway drawing it does not show a spring guide at all. I had a heavy steel guide at the front of the spring. This could be why it slams so hard. When I get it back together I am going to put the guide in the rear to see if it settles it down some. Got to do something to keep the scope on the rifle. FN...
Just checked my mail and the seals showed up today. So, will be working with that today and see where the fps goes. Keep you informed... FN
-
My seal is coming tomorrow or Monday.
I couldn't wait so I put her back together and took it out today.
Accuracy is very good I put a scope stop on it so thats not a worry any longer.
FPS didn't rise much but consistency is phenomenal. 10 shot string of Cros hollow points had a deviation of 3 fps 535 average.
Same went with most of the other more expensive pellets.
I saw a high today of 635 with Stencos and a low of 515 from Predators.
CHP's had me down to a cloverleaf at 20 yards.
It's really a satisfying gun to shoot
-
Have the 512 back together and chronied.. It averages out at 561 with Daisy Flat Nose, slightly over 14gr... I shot about 60 pellets.. The big test will be putting a scope on it and see if will stay put. I did place the guide to the rear by the trigger. Seems to shoot a bit softer with just as good FPS.. So I am going to leave it at that and work with the scope. Just hope the velocity stays about where it is at..... FN
-
I shot the 512 with a scope and it is accurate and seems to like most pellets. I only shot 10 yards due to bad weather here. With the new seal and putting the guide toward the trigger it did not upset the scope at all after about 100 pellets. It now shoot just over 600 with the Hobby pellet. With the 14 gr pellets it settled down to around 545. One hole shots come easy with this rifle so far at least at 10 yards. 20 yards may be different, will have to wait for warmer weather and less wind for that.. If it keeps shooting like it is now I am going to like it, so nice and light, easy to handle.... FN