357 Mag in 38 SPC Revolvers.

[tlawler]

Now there are airweight alloy-framed J-frames factory chambered for .357 magnum, something unthinkable just a few years ago. J-frames such as the Model 36 were not even factory-approved for +P .38 Special ammo for many years.

The primary reason why the .357 case was made 0.135" longer than the .38 Special was to prevent its use in .38 Special revolvers. Even at that, there were (and are) plenty of .38 Special revolvers around (US and foreign) with chambers that will readily accept .357 ammo (usually chambers bored straight through)

I've debated reaming the chambers on my 342Ti to be able to shoot .357 when I'm concealed carrying it. I'd still normally shoot .38 spec out of it for practice, but I like the extra 200 FPS and extra muzzle energy afforded by the .357 round in a defensive scenario.

The 342 cylinder is .03" shorter than my M66 cylinder, but still plenty long enough to allow a .357 to chamber(after reaming) and have enough clearance from the forcing cone to not cause over pressure issues.

 

[WR Moore]

Mine will NOT accept a JHP bullet pushed in from the front of the cylinder,
let alone the added diameter of the case, that is holding a bullet.

Time for a new cylinder, maybe?

I hope this is humor. If not, if you tried dropping a correct diameter bullet in the chamber from the back end of a S&W cylinder you'll usually find it won't pass through the cylinder. The throats are generally slightly smaller than bullet diameter. If the chamber reamer was a bit worn and cut oversize it might drop through.

 

[Doug M.]

While it is not a sound situation, remember that when the .357 Magnum came about, there were a lot of older .38 special revolvers that were not at all as strong as the N frame and it was much more likely to have a nasty kaboom. I strongly suspect, even though I will not be one to try it, that a modern good condition .38 would not fail (quickly) at least if one were able to chamber and fire a .357 round.

The .308 in a .270 is a much scarier scenario. IIRC, the .270 case is based on the .308 and oopsies can happen. That pressure must be pretty serious. This can also occur with one of the boutique rounds for the AR platform, I think maybe the .300 Blackout, for a similar reason. I don't have other ammo with which this could happen, so it is does not scare me directly.

 

[hkcavalier]

While it is not a sound situation, remember that when the .357 Magnum came about, there were a lot of older .38 special revolvers that were not at all as strong as the N frame and it was much more likely to have a nasty kaboom. I strongly suspect, even though I will not be one to try it, that a modern good condition .38 would not fail (quickly) at least if one were able to chamber and fire a .357 round.

The .308 in a .270 is a much scarier scenario. IIRC, the .270 case is based on the .308 and oopsies can happen. That pressure must be pretty serious. This can also occur with one of the boutique rounds for the AR platform, I think maybe the .300 Blackout, for a similar reason. I don't have other ammo with which this could happen, so it is does not scare me directly.

That's why I was wondering about that post...the .270 is a necked down .30-06, quite a bit longer than a .308. With a controlled feed rifle it would certainly fire and have a very generous chamber with which to work. Push feed, I would think it would close and lock just fine...but a gap for the firing pin to overcome to reach the primer. But just guessing here.

 

[dirtysanchez]

Wouldn't a worn reamer cut an UNDERSIZE chamber?