We've seen in current threads that S&W began using heat-treated cylinders on .38 Special M&P guns in Sept., 1919.


I get the impression that some feel this makes guns made after that date to be safe with Plus P ammo.


I'm sure they are safer from a blowup or a cracked cylinder, but frames and yokes were not changed metallurgically , were they?


If not, frequent use of hot ammo is going to cause cylinder endshake sooner than with later guns, made of improved steels and current heat treatment .


Keep in mind that some hot ammo is hotter than the rest . Buffalo Bore is surely loaded to higher pressures than most.


This is why I sometimes caution against Plus P in old .38's, despite what some have said about blowups not happening in their vintage revolvers.


Just a thought...

I cannot relate to people who would want to shoot +P out of older guns, frequently or otherwise.

As you indicate, hot ammo may be safe for the operator of the moment, but that doesn't mean it's necessarily good for the long term health of the gun.

Regardless of the pre- or post-hardened cylinder cut-off, on an old gun one never knows what the gun has been through, or rather what has been through the gun, during the previous decades or even century. The next round could be the one that breaks the camel's back. Out of all my collectible revolvers, I've always used only mild lead wadcutter target loads. A few post-war M&P's have served as home-defense back-up loaded with modern +P hollow points, and I'm sure they'd handle those just fine, but I just don't see the point of shooting hot loads for the heck of it.

Anyone who wants more noise and recoil should just get a .357 Magnum.

I do see a very significant need for Plus P, and some such loads can add 200 FPS or more over std. pressure ammo.


For self defense, including hiking where a man armed only with a .38 may encounter dangerous animals, I think Plus P can be a real blessing.


But I agree with Absalom that ROUTINE use of Plus P at a range or to shoot tin cans is not the best way to conserve gun life without repairs.


Still, some do that, and if an old .38 is in the family, it may be shot that way. I just wanted all here to be aware of the issues that can arise in such a situation.