end shake

[odis]

Hi, an internet friend just bought a 29-2 with a cylinder gap of .005 and .004 end shake. Is that acceptable and if not is it fixable with shim bearings? Thanks in advance for any advice.

 

[Laketime]

Hi, an internet friend just bought a 29-2 with a cylinder gap of .005 and .004 end shake. Is that acceptable and if not is it fixable with shim bearings? Thanks in advance for any advice.

.003 is considered ideal.

 

[odis]

.003 is considered ideal.

So if he fitted a .002 bearing he would have .002 end shake and a cylinder gap of .007 would that be a problem?

 

[Hapworth]

So if he fitted a .002 bearing he would have .002 end shake and a cylinder gap of .007 would that be a problem?

Those numbers are off. If the cylinder gap was measured correctly -- that is, with the cylinder held back while measuring -- shimming the endshake has no affect upon cylinder-barrel gap.

To make certain, too, that endshake has been properly measured: hold the cylinder forward and measure cylinder-barrel gap; hold the cylinder back and remeasure cylinder-barrel gap; subtract the smaller number from the large and that's endshake.

Per the Kuhnhausen manual, endshake up to .006" is considered in spec and can be left alone.

 

[odis]

I believe he found the gap at .009 with the cylinder pushed all the way back and forward .005 giving the revolver a .004 endshake. I also thought the bearing moves it back making the cylinder gap wider by the thickness of the shim.

 

[Hapworth]

I believe he found the gap at .009 with the cylinder pushed all the way back and forward .005 giving the revolver a .004 endshake. I also thought the bearing moves it back making the cylinder gap wider by the thickness of the shim.

The shim pushes the cylinder back; if he found .009" cylinder-barrel gap with the cylinder held back, that's what he'll find no matter how far he shims cylinder, because he'll still have to hold the shimmed cylinder back to correctly measure barrel-cylinder gap.

Shimming just replicates the act of holding the cylinder back by hand.

 

[Laketime]

So if he fitted a .002 bearing he would have .002 end shake and a cylinder gap of .007 would that be a problem?

.009 is way out of speck. I believe 006 is max with in range.and 002-003 is considered where you want it to lye.

 

[Hapworth]

.009 is way out of speck. I believe 006 is max with in range.and 002-003 is considered where you want it to lye.

I believe OP means cylinder-barrel gap is .009", not endshake. A c-b gap of .009 is in spec. You're correct, though, endshake should be no more than .006".

 

[odis]

I believe OP means cylinder-barrel gap is .009", not endshake. A c-b gap of .009 is in spec. You're correct, though, endshake should be no more than .006".

Yes thank you, he said the forward measurement was .005 and .004 end shake so I assume that means .009 gap.

 

[Nightowl]

.009 is way out of speck. I believe 006 is max with in range.and 002-003 is considered where you want it to lye.

Well, not quite. Smiths range for B/C gap used to be .004 to .010. I understand that .012 is now acceptable. The most popularly accepted best practice is .006. I personally do not like anything over .008, especially with magnums. But, if the endshake is set back .002 to .004 for this gun, B/C gap still would be within factory specs.

 

[Laketime]

I think you could be right here.I use to avoid buying magnums with anything bigger than 006 for shooting steel rams.This helped reduce top strap cutting with max hot loads.

 

[odis]

Thanks to you all that have responded, I not sure if he even checked it properly, up to now he has only shot a 9mm pistol so this is his first real handgun and he has been obsessing about getting one for quite awhile. He freaked out and posted an almost incoherent post about the end shake. I think he will love this gun both shooting it and reloading for it if he can find any brass in the present market.