handguns - actual bullets VS barrel diameters

[max popenker]

Hello

for some little project i need your help, because i do not have suh guns & ammo handy .

1. Can anybody please measure actual diameters of bullets of various most popular brands of 9mm, .38Sp and .357mag ammo?

especially, is there any difference in ACTUAL diameter of jacketed and lead bullets for .38 and .357?

2. what is diameter of .38/.357 and 9mm barrel bores, by lands and by grooves?

Thank you

 

[Old Fuff]

The .38 Special and .357 Magnum are the same, so far as the bullet is concerned. The only difference is the case length, which is longer on the Magnum to prevent its accidental use in an older .38 Special revolvers. In both the bullet is .358 in diameter.

The various 9mm. cartridges usually use bullets of between .355 to .356 diameter.

One can use 9mm bullets in a .38 or .357, although they are undersized for most barrels they are still close enough.

However using .38 or .357 bullets in a 9mm pistol may cause excessive pressures.

(Edited to add)

Most .38 Special and .357 Magnums barrels run between .356 to .358

Most 9mm barrels from between .354 to .356

You may find individual guns that are not to specification, and those are usually oversized for the cartridge/bullet they are chambered in.

 

[C.R.Sam]

Old Fuff covered it nicely.

In slugging a batch of 200 duty guns I found extremes...
Such as 9mm with .359 bore and .357 with .354 bore. Both extremes shot well enough tho.
.3535 is the tightest .357 bore I have seen documented.

Sam

 

[jsalcedo]

I've loaded reclaimed .380, 9mm bullets into 38 special and .357 cases and fired them with no problem, although in my gun the .355 keyholed.

 

[Jim K]

In spite of the use of the term "bore", the measurements given all seem to be bullet/groove diameter. I believe Max also asked about bore diameter, which should be about .008 less.

The bullet diameter is (ideally) the groove, not the bore diameter.

Jim

 

[Quantrill]

To expand a bit on the bore and groove diameters,; a .30 cal rifle (30-30, 30-06, 308 etc.) has a bore dia. of .300 and a groove dia. of .308. Bullets are sized to the groove diameter (in this case .308). The pistol diameters mentioned above are all groove dia. bullets.
There are many knowledgable shooters who say that REVOLVER pistol bullets should be sized to the cylinder (exit) diameter even if it is different than the groove dia. This applies mainly to lead alloy bullets, not jacketed bullets. Quantrill