Another suppressor question, bare with me folks.

Are gas operated firearms, DI, piston, etc. quiter than blow back when using a suppressor?

Say, if you used a DI .45 acp AR15 upper, vs a blow back upper, would the DI be signficantly quiter?

I was just pondering, and it seems like it would be quiter technically, but just thought I would ask.

Gas Piston in my opinion.

The GPU is the quietest I have heard yet and less gas out the ejection port.

I have only shot three different manufacturers of Pistons and three different manufacturers of Cans, so my experience is kinda limited.

Well you have a few different sources for noise.

Unburned gas
supersonic projectiles breaking the sound barrier
mechanical noise

I don't know from experience, but here are some things to consider.

A 45 ACP is a low pressure round and coming out of a carbine lentgh barrel it should have burned the majority of it's powder.

The projectiles are usually subsonic to begin with

This leaves us only with mechanical noise
- a large heavy reciprocating bolt in a blow back system will make a pretty significant slam home.
- a piston system has potential to make several noises as the piston strikes the bolt carrier, but they may all be quieter due to lower mass.
- a DI system has low mass and there shouldn't be much gas driving it (do they even use DI for pistol cal carbines or SMGs?)

I do know from experience that for some reason .45s seem to be difficult to supress.

Thanks guys




Yup, they are rare, but they exist.

http://bazookabrothers.com/products2.htm

now ya know why I'm havin them decision issues bro

Mechanical noise is not an issue

when shooting suppressed you hear the what sounds like the hard thump from a pellet gun from the rifle and super sonic crack of the round, which the crack is much louder than anything.

I stood roughly 35 yards away from my dad Tuesday while he was shooting my can and did not hear the rifle other than a pellet rifle sound, but the crack from the bullet echoed through the hollowers.

Like I said the SAS cans are quiter than a 22 shooting the privi or xm-193

A blowback 9mm is a lot quieter than DI 223. I've shot both side by side and the 9mm AR is quieter 'out of the box'.

Piston versus DI depends upon the type of piston. And also what is your desire from suppression??? super quiet, or reliability? What about gas blowing back into your face?

The HK 416, for example, blows gas out the front, while other designs blow it into the area inside the handguard.

All things being equal, a DI is more quiet than the HK416 becuase the gasses on a DI are blown into the chamber, wile the 416's gasses exit into the air. this makes the 416 a rather poor suppressor platform if you are looking for maximum suppression. OTOH, if you are looking for reliability and the least amount of gas blowback into your face, the HK416 is one one of the best suppressor platforms.

Heck if I know, but I'm on a diesel truck site where a guy was saying he does not like Glocks cuz he had a Glock of some kind that was the loudest pistol he had ever shot...

^And thats why he's on a diesel forum.