64-3 troubles

[gunguy0829]

I have a S&W 64-3 (38 spl) 4", Today while shooting I noticed on the Federal steel cased 158gn. +P ammo had a bulge at the base after firing and the CCI alum. cased 158gn. LRN on two of 6 split the case, the cylinder has been machined to accept moon clips to shoot 9mm. Most of the 9mm shot fine had 2 or 3 that seemed a little too quiet as if they fired with low pressure, that ammo was 115 gn FMJ Federal. Any thoughts. A side note, I used to own this exact gun, traded it away and got it back, never shot anything but regular pressure brass cased ammo before. Is it the ammo or the cylinder, any ideas?

 

[Viper225]

Very simple fix.
Shoot 9mm which it has been rechambered for. Problem solved.
No more split or bulged 38's.

The 9mm Case is tapered .391 at the back of the case to .380 at the front.
The 38 Special is straight walled and .379 in diameter.

The 9mm being .391 at the back while the 38 Special is .379 is the problem causing the bulged and split 38 cases.

Bob

 

[gunguy0829]

Not sure the cylinders were bored out, when I owned this gun the last time, I never had this issue. What would cause some of the 9mm to be noticeably quieter ( 3 out of 30), its good ammo (Think I said federal but it is Winchester) I never had an issue with out of an autoloader.

 

[MikeJackmin]

Where the quiet rounds all from one chamber?

Did your gun have problems with .38 special brass after it was cut, but before you traded it?

 

[gunguy0829]

I got the gun already cut, never had an issue, the quiet rounds I dont think were from the same chamber and didnt always do it. I could fire 6 and no issue and the next 6 might have one that would do it, I am going to shoot it again and mark the cylinders that shoot quiet to see if its the same one or not.

 

[rcmodel]

Dup post in Gunsmithing:
http://www.thehighroad.org/showthread.php?t=691162&p=8592412#post8592412