Question About J Frame Barrel

Stingray77080 · #1 07-31-2020, 10:46 AM

Please forgive me if this seems like a dumb question, but I'm new to guns in general, and this is the only hand gun that I've ever owned.

I bought a 642 in .38 caliber a while back from a friend. It's a SPL+P. I bought some ammo for it this week and noticed that the cartridge fits in the cylinder just fine, and fits in the "back side" of the barrel. And just to get to know the gun better, I tried to fit the bullet in the front of the barrel. And to my amazement, it doesn't go all the way in. I took the ammo and gun back to the place I bought the ammo, and the guy there told me it's supposed to be like that to give the gun better accuracy.

Is this normal? Was the barrel actually designed with a taper in the barrel? I certainly don't want to fire the gun without knowing.

Thanks in advance.

riverrat38 · #2 07-31-2020, 10:58 AM

It should be tapered the other way, but, due to the tight fit of the barrel to frame threads, this is more or less normal. With lead bullets, there is actually a slight loss of accuracy, probably not noticeable in a M442. For best accuracy, it would be better if the taper was the other way around. But, that would be custom work.

Best,
Rick

armorer951 · #3 07-31-2020, 10:59 AM

The portion of the revolver barrel at the extreme breech end or barrel extension is called the "forcing cone", which is a slightly larger and tapered opening to allow the bullet to enter the barrel. The barrel itself, while not tapered, is sized slightly smaller (usually .002" - .003") than the projectile....this constriction traps the expanding gasses behind the bullet, while the lands and grooves in the barrel impart a "spin" to the bullet for stabilization. The dimension between the "lands" in the barrel is referred to as the "caliber".....which is in your case .357".

Based on your description, your revolver barrel sounds normal to me. Hope you enjoy shooting your 642.

Pine_Worker · #4 07-31-2020, 11:09 AM

Quote:

Originally Posted by armorer951

The portion of the revolver barrel at the extreme breech end or barrel extension is called the "forcing cone", which is a slightly larger and tapered opening to allow the bullet to enter the barrel. The barrel itself, while not tapered, is sized slightly smaller (usually .002" - .003") than the projectile....this constriction traps the expanding gasses behind the bullet, while the lands and grooves in the barrel impart a "spin" to the bullet for stabilization. Your revolver barrel sounds normal to me.

What 951 said! It is not a muzzle loader.

kaaskop49 · #5 07-31-2020, 11:48 AM

^^^what the others said. BTW, there are NO dumb ?s if you don't know something. That's the beauty of this forum. Good luck and good shooting!

Kaaskop49
Shield #5103

torizus · #6 07-31-2020, 12:15 PM

Post a pic of the bullet/round you are using, the bottom end of the case that has the manufactures abbreviation and the caliber of the ammo is the only definitive way for someone to clearly advise you if that is the correct ammo.

two-bit cowboy · #7 07-31-2020, 12:21 PM

Welcome aboard and to the revolver world.

Armorer gave you the expert answer, now go learn and enjoy shooting your 642.