Revolvers that fire .357 magnum and .38 special
 

I have read that revolvers chambered for .357 magnum can fire .38 rounds also. Is there a performance penalty in these revolvers when firing .38 rounds?

not really. They accuracy may be slightly decreased, but not by much.

Actually, .38, .357, and 9mm Luger/Parabellum all have projectiles of roughly equal (.35x") diameter. The loose tolerance on revolvers like the S&W .357 Magnum allows it to fit a .38 round in there.

Edit: Aside from unoptimized rifling, which isn't likely to make a difference in a revolver which has a 4" barrel, there shouldn't be a noticeable problem.

What I mean is I can go buy a factory made ammunition, one made for a .38 special, the other for .357 magnum and use them, casing and all in the same gun. I am not talking about using a .38 bullet inside a .357 magnum casing.

Yes.

And just to be clear, we are talking about a .357 revolver being able to shoot .38 specials. This does not work for automatics or for .38 revolvers (they CANNOT shoot .357 due to the fact that they are sized for the shorter .38 cartridge and the .357 won't fit.)

.357 magnum is accurately named. The bullet is approximately .357 in diameter. .38 special comes from an earlier era when calibre naming conventions were creative, and mostly based off of black powder conventions (such as ".44 magnum" actually being .424 or so). The .357 magnum is actually a child of the .38 special in that there was a load called .38-40 HD that came about in the 20's which was, in essence, a .38 special case loaded to .357 magnum pressures, and was designed to be fired only in guns that carried the .38-40HD designation.

Well, needless to say, if it fits in a gun, people will shoot it, so there were quite a few .38 special handguns destroyed by use of .38-40HD rounds being put through them. The ammo and gun manufacturers got together and decided to correct the problem by creating a round that was the same overall dimensions as the .38 special with the exception of being 1/8th of an inch longer, thus preventing it from beign chambered in the .38 specials of the day.

Smith & Wesson was the revolver maker involved with the ammo manufacturer (Remington? I know they made the .44 mag, but I am not sure if they made the .357) that created the round, and they produced the M-27 to handle the load. There is still debate over where precisely the "magnum" designation came to play and who named it such. Nonetheless, the round and revolver was a spectacular success, and was the single most popular choice for law enforcement in rural areas for quite some time. It is still one of the best manstoppers in production.

It is perfectly safe to fire .38 special round in a .357 magnum gun, and many people practice shooting this way as it is far less expensive than magnum ammo. It is also perfectly safe to use .38 bullets in a .357 magnum case as well, as they are precisely the same thing (.38 special loads tend to be lighter grain weight, but that matters little).

The only performance penalty, beyond the expected lower velocity of the .38 special, would be the increased distance between the bullet and the forcing cone. Proper accuracy in revolver relies heavily on the forcing cone. That 1/8th inch isn't much, but it can be significant if you are looking for truely precise shooting. For the average joe though, there is no appreciable difference aside from velocity.

It's fine and a hell of a good idea for practice but be damn careful a .357 in a 38 is a very bad idea!!!!

Not to mention, impossible.

(Did you read the thread?)

I have a S&w model 19 tells you in the paper work it can handle both 357 and 38

Moonducks info is accurate and the Magnum designation came from a variety of incedents that were related to giving a name that created the image of a greater amount( in this case a greater a greater amount of power. The name originates ( you laugh about this but it is true) from the French term Magnum from a Magnum of Champagne which was a larger bottle than a whine bottle. Don't that beat all.
Source is from the Histroty of the Gunb /story of John M. Browning discory times channel.

The first time I fired a .357 we used .38 rounds and .38 +p's first. Then we switched to .357 rounds. What a difference! Flame shot out the end of the barrel, and people shooting nine millimeters and .22's turned and looked to see what was happening. The gun was very accurate and fun to shoot. I have a Beretta .40, which I like, but my next choice would be a .357 revolver, and then a .22 for target practice.

I should've mentioned the magnum Champagne idea, but was more interesting, gun geek that I am, in relating the fact that no one has been able to pin down who it was that added the term magnum, or when, in the design process, it occurred.

(At least that is accurrate as of the last time I dug into it. More data may have surfaced.)

As an aside, if you get used to shooting .357 magnum accurately, you can then change to .38 special to pull of cute tricks. I used to print a smiley face onto the head of an FBI "Q" target to win bets with my friends. Always did it with .38 special wadcutters as they leave such nicely precise holes in the paper.