9mm ar-15

[GS1458]

Hello All,

Have on order a Rock River 9mm Upper, for my AR-15. What size cast bullets are you guys using in them? I can't get an answer from RR on the groove dia of there BBL's.

I have a bunch of 147 grain TC that I use in my Cowboy Rifles sized .357 would like to use them or resize them if need be.

Thanks to all that respond.

[GrizzLeeBear]

Don't have one (9mm AR that is), but if you do some searching on 9mm you will see that they can run from .355 to .358. A lot of guys size to .357 or .358 for the 9mm. When you get the upper, just slug the bore and size to .001 or .002 larger.

[medicstimpy]

I run both RCBS 124gr RN and Lee 105gr SWC's out of my RRA 9mm AR. The little Semi-wad's are great! :evil:

I size them to .356 and use Lars's Red Carnuba. The RCBS is a GC design, but I don't bother with the GC.

I could actually get slightly better results sizing them to .357 for the AR but I just size them all to .356 (best for my XD9) so I don't have to have two separate boxes of 9mm. The difference on paper at 25, 50 and 100m with the AR wasn't enough to worry about. If I want that much accuracy, that's what the 20" .223 AR is for. :)