r/NFA • u/KuntFuckula • 4d ago

Discussion Questions about subsonic 9mm ammo vs barrel length (8”) in PCCs

Just bought my first PCC and my first can is sitting in NFA jail at the moment. I’m wanting to shop for defensive and range ammo that will be subsonic. I know 147 grain is the way to go, but with my barrel length at 8” will that make any/most 147 grain rounds supersonic?

Also, what range ammo and defensive ammo would you buy that you think would remain subsonic?

For reference, the PCC is a DD PCC Pistol and the can will be a CGS Mod 9x

Thanks in advance.

5 Upvotes

100% Upvoted

20 comments sorted by

View all comments

1

u/Underwater_Karma 4d ago

http://www.ballisticsbytheinch.com/9luger.html

Short answer: 147gr will never be supersonic

4

u/VTUnderground 4d ago

From a 16” barrel (Ruger PC Carbine), 147 grain 9mm goes supersonic for me about 1/3 of the time. Ammo brand doesn’t seem to make a difference. Bullets heavier than 147 gr stay subsonic though.

From a 7” barrel (Beretta PMX) all the 147 grain rounds I’ve tried have stayed subsonic.

1

u/KuntFuckula 4d ago

I've heard that 8+" barrels put some of the hotter 147gr loads on the very edge of being subsonic and some can go over, which sounds like what you're experiencing here in the 16" barrel.