MP 512M Barrel ID

[dank]

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??

[fnash]

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

[Gene_SC]

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

[fnash]

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

[Gene_SC]

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

[fnash]

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

[Gene_SC]

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

[fnash]

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

[Gene_SC]

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

[fnash]

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

[Gene_SC]

It does not have to be solid...:)

Gene

[dank]

EEA shows an exploded view of the 512 only Not the 512M;

 http://www.eaacorp.com/diagrams-mp512lg.html

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.

[dank]

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.

[dank]

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.

[howie1a]

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