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View Full Version : AR cyclic noise


rumlover
02-08-2011, 09:33 AM
All,

Related to the AA9 post....but different issue....same weapon and 50 round trial.

Even when rounds were below 1020fps, I still could hear a lot of noise that sounded like it was report, not the weapon cycling. It was on the order of a 22LR.

The question: For those of you with an adjustable gas block, is the difference in sound much greater when the gas is shut off v/s on?

Thanks,
Rum

buffetdestroyer
02-08-2011, 02:18 PM
A lot of what you are hearing on an AR is the spring and the buffer through the stock (remember that sound travels better through solids).

Their is a decent pop similar sounding to an air gun when shooting with the gas block off. You can easily hear it on videos of bolt guns suppressed on Youtube.

The best thing to hear what your gun sounds like is to have a buddy shoot it and you stand safely to the side or behind him while shooting. It is always quieter when your head is not touching any part of the firearm. Where you stand will also affect your perceived hearing as the gas from the ejection side will likely be louder than on the opposite side where no gas is coming out. I will often times hold the weapon at arms length to evaluate the sound and it always seems much quieter than when I am holding it with a proper cheek weld.

Typical actions that I have seen metered were between 100 and 115 decibels and it is not very likely that you will get below that with anything other than a .22.

i8asquirrel
02-08-2011, 04:46 PM
I have noticed what destroyer say to be true. when I shoot my ar it seems Loud, BAng,rattle ,sproing, clump!! but when you ar eoff the side and dont have an ear pressed to the stock she sound pretty good..certainly not like a rifle being fired!:grin:

BLAKE2131
02-16-2011, 01:10 AM
rum do you have a suppressor on the gun if not the escaping gas from the muzzle is what you are hearing even though you have sub sonics youll still have muzzleblast without a can

BWE Firearms
02-16-2011, 08:01 AM
Action noise is always loader when you are shooting the gun especially semi auto or full auto guns.

rumlover
02-18-2011, 04:30 PM
Expectation management I suppose. Typically when I'm shooting an autoloader with a can, it's high velocity ammo I'm using. This is my first auto/subsonic toy so all the extra bullshit wrattling around inside was louder than expected. Although I could swear that I was hearing a crack at 1000fps and only 40 degrees. I'm headed back out with some new loads this weekend and will report back.

Guess I'm spoiled after shooting only bolt guns with cans and subs all these years...and that's a good problem to have.

i8asquirrel
02-18-2011, 04:50 PM
Real expectations are the Key..
It may not sound like a Movie silencer but it quiter than you think if your the shooter. Many times My buddy and I will be seperated while hunting and I will make a kill and he wont have even heard the shot.
Being ready and listening for the discharge of a weapon or just having one fired when real world noise and events are taking place can make an amazing difference....:grin:

HotLead
02-21-2011, 04:22 PM
Just shot mine today...when I wasn't shooting I was standing 1-2 yards away; it seemed much quieter than when I was pulling the trigger.

Do you have the ability to turn your gas off? I turned my gas block to the OFF position for effect to show the other guys just how quiet it can be.

My load (for a 16" barrel) is: 11.5grains of IMR 4198, Sierra 190gr HPBT MK, seated to 2.235" OAL. The Temperature today was 35 degrees and this gave me 985fps. Speed of sound here today should be roughly 1090 fps. At 12.0 grains of 4198, some of the loads were going supersonic.

Retooferab
02-21-2011, 07:08 PM
A Tubbs flat wire buffer spring will help with the noise.