9mm Bore /groove diameter

[williamwaco]

I have been preaching for years that I have never seen a 9mm with a .355 grove diameter. They are all larger than that.

Well . . .


Now I have. And no. They are not.

I have a new Kimber Stainless Steel Target model.

It measures .3482 / .3546

Sorry about all that past misinformation.

[JeffG]

That's pretty wild. Well, how does it shoot? Inquiring minds want to know.:popcorn:

[rsrocket1]

I have been preaching for years that I have never seen a 9mm with a .355 grove diameter. They are all larger than that.

Well . . .


Now I have. And no. They are not.

I have a new Kimber Stainless Steel Target model.

It measures .3482 / .3546

Sorry about all that past misinformation.
My M&P full size 9 and Shield 9 barrels slugged at .3545". The throats are .356" and a .356" sized bullet chambers perfectly with no room to spare. A .357" bullet will often hang the slide and need additional persuasion to close it so I have to be sure all bullets are sized and do a plunk test with every completed round. The reward I get is no hang ups when shooting and zero leading, but the PC really helps prevent the latter.

[Bzcraig]

At least you're man enough to own it, that is admirable.

[ioon44]

The Kimber must be an exception, all 9 mm barrels I have dealt with are .356" to .3575".
I just measured 3 different Ruger SR 9 barrels one is .3575" and the other 2 are .357".

[williamwaco]

The Kimber must be an exception, all 9 mm barrels I have dealt with are .356" to .3575".
I just measured 3 different Ruger SR 9 barrels one is .3575" and the other 2 are .357".


That agrees closely with my prior experience.

[williamwaco]

That's pretty wild. Well, how does it shoot? Inquiring minds want to know.:popcorn:

Too early to tell.
I am loading test ammo this afternoon.

[Cherokee]

My King and Briley barrels measure .355, but they are aftermarket barrels. Been using 356 size for years and they are great.

[Freischütz]

All my 9mm pistols are military, and .357-.359" diameter bullets produce the best results.

I've found throat diameters vary wildly. Nothing would surprise me. Without barrel measurements I never consider using cast bullets in a 9mm.

[tazman]

Taurus PT92 AFS pistols are the only 9mm pistols I have experience with. The factory barrels slugged at .356-.3565. They shot fine with jacketed but not so well with cast.
The Beretta barrels I installed in my Taurus PT92 pistols made a world of difference in the accuracy department. The chambers are on the larger side and will eat anything within reason and a few things that aren't. These barrels will actually chamber a case loaded with a .360 boolit without any problems although they don't shoot as well as those sized .358.
The groove diameters, of course, are a bit on the large side also. They measure at .357- .3575 as close as I can mike the slugs.
The difference between the Taurus barrels and the Beretta barrels is in the width and depth of the lands. The Beretta barrels have both wider and deeper lands. This seems to allow the boolits to grip the rifling better, hence the increased accuracy.
The bottom line----with the Beretta barrels, these pistols are utterly dependable and very accurate. I can't remember the last time I had a failure to feed, fire, or eject with them. I would and do trust them with my life.

[Boolit_Head]

I can't remember who it was maybe it was Kimber that used the same barrel stock for 9mm and 38 super. That would account for the smaller diameter I believe.

[JeffG]

Too early to tell.
I am loading test ammo this afternoon.

Cool!