Title says it all. If I fire standard 147 grain 9mm from a suppressed 16 inch barrel PCC - in my case a Keltec Sub 2k - will it remain subsonic? Tried a google search but did not find a clear answer. Thanks

Probably, but it'll be close.

147 grain 9mm gains ~100 fps going from a 4" handgun barrel to a 16" rifle barrel.

Most 147 grain 9mm is doing 1000 FPS or a bit less out of a 4" test barrel.

So 1000ish + 100ish means that should still be subsonic (a bit below 1125), even out of a 16" barrel. But some loads might just cross over the threshold of being supersonic at the muzzle.

Ballistics by the inch fired Federal 147 grain Hydra-shoks out of a Keltec and recorded a mv of 1086. That is about 40 FPS below the speed of sound (assuming sea level, standard day). I would guess that some rounds would be supersonic due to manufacturing variations. link

As usual, Rogue beats me to the punch

wow! you guys are good! Appreciate the responses. I was just going to buy a case of 147 but maybe I will start with just a few boxes and see how it goes.

So next question. Is there any 9mm designed to be subsonic from a 16 inch PCC?

There are some 158gr offering out there that would reliably stay subsonic out of a 16” barrel. I bought a case of this a few years back; I’m still slowly shooting through that case, no issues with it.

So I started looking around and I found this link 165 grain FMJ offering made by Ammo Inc. I don't know anything about this ammo or manufacturer, but it should definitely stay subsonic.

I was not even aware these heavier weight rounds existed. Going o get a few boxes of each if i can find them and try them all out. In a perfect world the 147 grain will stay subsonic, at least that's my hope.

Appreciate the responses.

I haven’t tried that brand of 165 but my Hush 165 ammo is pretty quiet but doesn’t reliably cycle. I have had good luck with fiocchi 158gr in my pccs.

I may be able to help with a few clear answers with some heavier bullets. Velocities vary in individual guns, but in my 16" carbine the following factory rounds produced the listed chronographed velocities: Standard pressure Speer 147 Gold Dot= 1001 FPS, Speer LAWMAN 147= 1143 FPS, Federal HST 147+P= 950 FPS, IMI 158 grain= 891 FPS. These all cycled reliably in my Marlin Camp Carbine.

very helpful. Thanks

I have had god luck with the Fiocchi 158 gr out of my Ruger PCC. It cycles fine.