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Is all 9mm 147 grain sub sonic fired out of 16 inch barrel PCC

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March 22, 2023, 03:23 PM
kho
Is all 9mm 147 grain sub sonic fired out of 16 inch barrel PCC
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
March 22, 2023, 03:36 PM
RogueJSK
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.
March 22, 2023, 03:39 PM
Herkdriver
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



"I, however, place economy among the first and most important republican virtues, and public debt as the greatest of the dangers to be feared." Thomas Jefferson
March 22, 2023, 03:56 PM
Herkdriver
As usual, Rogue beats me to the punch Smile



"I, however, place economy among the first and most important republican virtues, and public debt as the greatest of the dangers to be feared." Thomas Jefferson
March 22, 2023, 04:02 PM
RogueJSK
Big Grin
March 22, 2023, 04:07 PM
kho
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?
March 25, 2023, 04:18 AM
SigM4
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.



Success always occurs in private, and failure in full view.

Complacency sucks…
March 25, 2023, 10:27 AM
Herkdriver
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, however, place economy among the first and most important republican virtues, and public debt as the greatest of the dangers to be feared." Thomas Jefferson
March 25, 2023, 01:42 PM
kho
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.
March 25, 2023, 03:31 PM
Chowser
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.



Not minority enough!
March 27, 2023, 09:25 PM
rock185
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.


NRA Life
March 28, 2023, 03:32 PM
kho
very helpful. Thanks
March 28, 2023, 07:12 PM
shoevb
I have had god luck with the Fiocchi 158 gr out of my Ruger PCC. It cycles fine.