Suppressors on bolt or semi auto guns. Difference?

Pond, James Pond · November 24, 2016, 06:03 AM

I'm just trying to establish from anyone who has had real world, side-by-side experience if there is any noticeable difference in suppressor effectiveness when on a semi auto or bolt gun.

For example:

If the same suppressor were fitted to a CZ 527 in 7.62x39 and then to a VZ58 would one be noticeably quieter than the other?

Leaving aside barrel length, my guess is the opening breech of the semi auto and the thinner chamber section would make it a bit louder but am I wrong?

Double Naught Spy · November 24, 2016, 09:16 AM

The biggest noise from the semi-auto is the sound of the action. Thinness of the chamber has nothing to do with it. Keep in mind that suppressors are exceptionally thin by comparison.

Machineguntony · November 24, 2016, 10:53 AM

The sound difference is minimal. I've heard two similar suppressed calibers discharge next to each other, one gun being a bolt and one a semi auto, and I couldn't tell which gun was which.

The biggest issue is the gas blowback. No matter what steps you take to minimize the blowback, a semi auto will always have some amount of blowback that gets in the shooters face.

Pond, James Pond · November 24, 2016, 01:30 PM

Quote:

The biggest issue is the gas blowback. No matter what steps you take to minimize the blowback, a semi auto will always have some amount of blowback that gets in the shooters face.

That is good to know.

That might be one argument for buying a shorter can.

My only experience is on a .22 and on a .308 bolt gun. The .308 is still loud but well within tolerable ranges without ear protection (I do still wear protection, but wanted to hear it once without).

A VZ58 is a lower pressure cartridge, so I imagine the shockwave is lower to begin with and so if I get similar suppression to the .308 it should be much quieter but with more blowback, or a shorter can will be louder but perhaps reduce blowback.

Would that be correct reasoning?

Mobuck · November 25, 2016, 08:13 AM

I don't notice much "blowback" with the AR platform. We use "gas buster" charge handles on the most often used host rifles but really don't notice a problem even with mil-spec CH. The most noticeable is the 22 lr pistols.

Deja vu · November 25, 2016, 12:03 PM

I know for 22lr it does make some difference. I have a Ruger 10/22 and a Chipmunk single shot. The single shot is quieter. But unless you are comparing them side by side I doubt you will hear it. Especially if your not the shooter (the action is very close to your ear).

rjrivero · November 25, 2016, 03:19 PM

If it's a blowback action then you will notice a difference 9mm AR's are louder than HK MP5's with their delayed roller action.

.22 semis are louder than .22 bolt actions.

But, it seems that most of this "noise" is worse for the shooter than the people observing. If that makes a difference.

Pond, James Pond · November 26, 2016, 03:58 AM

Some background to my question:

As some may know I've repeatedly come back to the VZ58 and as it happens one shop would do me a decent deal on the rifle and a suppressor.

The offer was based around a stubby 4" can (22-24dB drop), but I could spend a very modest amount more and get a full 8" can (26-28dB drop) as I already have on my .308.

My question was to give me an idea if the short can could give me suppression to comfort levels or do I still need to go to the big can, sacrificing weight and length advantages, to get adequate sound levels.

And of course the M'guntony's point about blowback:

My guess is that the longer can, offering more resistance to gas expansion, will result in more blowback.

Any thoughts on those specifics?

9x19 · November 26, 2016, 07:23 AM

Wouldn't the increased internal volume of the longer can create less blow back?

Not a silencer guy, so don't rally know... but I am curious.

AK103K · November 26, 2016, 08:14 AM

Is blowback into the shooters face really an issue with anything but the direct impingement guns like the AR's?

I have a number of AR's that are hosts for my AAC M4-2000 suppressor, and Ive had to deal with gas in the face with all of them. Some are worse than others, but all have some level of gas seal type treatment used to keep it to a minimum.

At least for me too, the issue doesnt really crop up, or at least isnt near as bad, unless Im shooting a lot of rounds quickly.

As far as the original question about difference in sound between them. I also have a bolt gun that takes the same suppressor as the AR's, and I dont notice any real difference in sound as far as the shot goes, and thats shooting them without ear protection.

The only thing I do really notice is, the mirage coming off the suppressor when its on the bolt gun becomes an issue very quickly with the scope and trying to acquire the target. My one AR also has a scope, and I dont have the issue with it.

I suppose it may be time for one of those mirage reducing can covers.

MarkCO · November 26, 2016, 08:22 AM

With DI guns, the nice thing is you can tune the gas and the load to reduce the gas the shooter has to deal with...to irrelevant levels.

Blowback guns are going to be a little louder than DI guns which are going to be a little louder than manually operated guns.

Pond, James Pond · November 26, 2016, 10:15 AM

The VZ58 is a piston gun like the AK, is it not?

So how do they affect the likelihood of blowback?

Mobuck · November 26, 2016, 10:07 PM

If the action has a solid rear face, the "blow back" shouldn't bother the shooter much (or any).

November 24, 2016, 06:03 AM	#1
Pond, James Pond Senior Member Join Date: July 12, 2011 Location: Top of the Baltic stack Posts: 6,079	Suppressors on bolt or semi auto guns. Difference? I'm just trying to establish from anyone who has had real world, side-by-side experience if there is any noticeable difference in suppressor effectiveness when on a semi auto or bolt gun. For example: If the same suppressor were fitted to a CZ 527 in 7.62x39 and then to a VZ58 would one be noticeably quieter than the other? Leaving aside barrel length, my guess is the opening breech of the semi auto and the thinner chamber section would make it a bit louder but am I wrong? __________________ When the right to effective self-defence is denied, that right to self-defence which remains is essentially symbolic. Freedom: Please enjoy responsibly.

November 24, 2016, 09:16 AM	#2
Double Naught Spy Senior Member Join Date: January 8, 2001 Location: Forestburg, Montague Cnty, TX Posts: 12,717	The biggest noise from the semi-auto is the sound of the action. Thinness of the chamber has nothing to do with it. Keep in mind that suppressors are exceptionally thin by comparison. __________________ "If you look through your scope and see your shoe, aim higher." -- said to me by my 11 year old daughter before going out for hogs 8/13/2011 My Hunting Videos https://www.youtube.com/user/HornHillRange

November 24, 2016, 10:53 AM	#3
Machineguntony Senior Member Join Date: June 22, 2013 Posts: 1,277	The sound difference is minimal. I've heard two similar suppressed calibers discharge next to each other, one gun being a bolt and one a semi auto, and I couldn't tell which gun was which. The biggest issue is the gas blowback. No matter what steps you take to minimize the blowback, a semi auto will always have some amount of blowback that gets in the shooters face. __________________ Sent from Motorola DynaTac 8000x

November 25, 2016, 12:03 PM	#6
Deja vu Senior Member Join Date: March 14, 2010 Location: Border of Idaho & Montana Posts: 2,584	I know for 22lr it does make some difference. I have a Ruger 10/22 and a Chipmunk single shot. The single shot is quieter. But unless you are comparing them side by side I doubt you will hear it. Especially if your not the shooter (the action is very close to your ear). __________________ Shot placement is everything! I would rather take a round of 50BMG to the foot than a 22short to the base of the skull. all 26 of my guns are 45/70 govt, 357 mag, 22 or 12 ga... I believe in keeping it simple. Wish my wife did as well...

November 26, 2016, 03:58 AM	#8
Pond, James Pond Senior Member Join Date: July 12, 2011 Location: Top of the Baltic stack Posts: 6,079	Some background to my question: As some may know I've repeatedly come back to the VZ58 and as it happens one shop would do me a decent deal on the rifle and a suppressor. The offer was based around a stubby 4" can (22-24dB drop), but I could spend a very modest amount more and get a full 8" can (26-28dB drop) as I already have on my .308. My question was to give me an idea if the short can could give me suppression to comfort levels or do I still need to go to the big can, sacrificing weight and length advantages, to get adequate sound levels. And of course the M'guntony's point about blowback: My guess is that the longer can, offering more resistance to gas expansion, will result in more blowback. Any thoughts on those specifics? __________________ When the right to effective self-defence is denied, that right to self-defence which remains is essentially symbolic. Freedom: Please enjoy responsibly.

November 25, 2016, 08:13 AM	#5
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	I don't notice much "blowback" with the AR platform. We use "gas buster" charge handles on the most often used host rifles but really don't notice a problem even with mil-spec CH. The most noticeable is the 22 lr pistols.

November 25, 2016, 03:19 PM	#7
rjrivero Senior Member Join Date: November 17, 2008 Location: NW Ohio Posts: 1,399	If it's a blowback action then you will notice a difference 9mm AR's are louder than HK MP5's with their delayed roller action. .22 semis are louder than .22 bolt actions. But, it seems that most of this "noise" is worse for the shooter than the people observing. If that makes a difference.

November 26, 2016, 07:23 AM	#9
9x19 Senior Member Join Date: October 15, 1998 Location: Sherman, TX USA Posts: 3,750	Wouldn't the increased internal volume of the longer can create less blow back? Not a silencer guy, so don't rally know... but I am curious. __________________ Make mine lean, mean, and 9x19!

November 26, 2016, 08:14 AM	#10
AK103K Senior Member Join Date: May 1, 2001 Posts: 10,223	Is blowback into the shooters face really an issue with anything but the direct impingement guns like the AR's? I have a number of AR's that are hosts for my AAC M4-2000 suppressor, and Ive had to deal with gas in the face with all of them. Some are worse than others, but all have some level of gas seal type treatment used to keep it to a minimum. At least for me too, the issue doesnt really crop up, or at least isnt near as bad, unless Im shooting a lot of rounds quickly. As far as the original question about difference in sound between them. I also have a bolt gun that takes the same suppressor as the AR's, and I dont notice any real difference in sound as far as the shot goes, and thats shooting them without ear protection. The only thing I do really notice is, the mirage coming off the suppressor when its on the bolt gun becomes an issue very quickly with the scope and trying to acquire the target. My one AR also has a scope, and I dont have the issue with it. I suppose it may be time for one of those mirage reducing can covers.

November 26, 2016, 08:22 AM	#11
MarkCO Senior Member Join Date: October 21, 1998 Location: Colorado, USA Posts: 4,307	With DI guns, the nice thing is you can tune the gas and the load to reduce the gas the shooter has to deal with...to irrelevant levels. Blowback guns are going to be a little louder than DI guns which are going to be a little louder than manually operated guns. __________________ Good Shooting, MarkCO www.CarbonArms.us

November 26, 2016, 10:15 AM	#12
Pond, James Pond Senior Member Join Date: July 12, 2011 Location: Top of the Baltic stack Posts: 6,079	The VZ58 is a piston gun like the AK, is it not? So how do they affect the likelihood of blowback? __________________ When the right to effective self-defence is denied, that right to self-defence which remains is essentially symbolic. Freedom: Please enjoy responsibly.

November 26, 2016, 10:07 PM	#13
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	If the action has a solid rear face, the "blow back" shouldn't bother the shooter much (or any).