[Wizard]

I'm confused now....

I always thought that the dia. sizes went like this:

9mm Luger 356
.380 Auto 355
.38 Super 355

I'm getting read to put in an order for 9mm FMJ at Midway, and I'm seeing 9mm sized to 355. Is this because it is FMJ, and lead is sized at 356???

 

[COFFEE POT]

Either one will work. Your barrel dimensions have a +.oo4" manufacturing tolerance on the bore and groove dias per SAAMI spec. .355/.356 are both commonly used in 9mm.

 

[Wizard]

Thanks, Coffee Pot. I appreciate the info.

 

[454PB]

I use home cast bullets almost exclusively. In 9mm, I size them .358. Using .355" jacketed in the same guns works fine.

The 9mm has a bad reputation with cast bullets, and it's mostly caused by shooters using undersized bullets. With the shallow rifling and fast twist, you need a cast bullet to be .002" to .003" over bore diameter.