This Ping List is for all news pertaining to infringes upon or victories for the 2nd Amendment.
FReepmail me if you want to be added to or deleted from this Ping List.
More 2nd Amendment related articles on FR's Bang List.
Posted on 03/20/2023 5:44:07 AM PDT by marktwain
Everyone who has listened to gunshots in close proximity knows some cartridges are much louder than others. In the other direction, some cartridges are much quieter than others.
Everyone understands a .22 LR out of a rifle is much quieter than a .338 magnum out of a rifle.
Not as widely understood, loads for the same cartridge vary widely in how loud gunshots are perceived. The .22 Long Rifle cartridge is a good example. The highest energy .22 LR cartridges, such as the Aguila Interceptor and the CCI Velocitor, are much louder than CCI Standard Velocity, even though all are firing 40-grain bullets. Further down the scale, the CCI Quiet .22 load is much quieter with a 40 grain bullet than the Standard velocity. The 29-grain CB load is even quieter. The Aguila 20 grain primer-powered Super Colibri load is still quieter. It makes less noise than many pellet guns.
A key difference in how loud a load sounds is whether the bullet goes supersonic or stays subsonic. To be very quiet, a load must operate in the subsonic area. Projectiles should have an average muzzle velocity of 1070 fps or less to stay sub-sonic reliably. The speed of sound depends on the temperature. At 70 degrees Fahrenheit, the speed of sound is 1128 feet per second. At freezing (32 F), the speed of sound is 1087 fps. At 100 degrees F, the speed of sound is 1158 fps.
For a particular load in a particular cartridge, the length of the barrel makes a considerable difference in how loud the discharge of the cartridge sounds.
An Aguila 20-grain Super Colibri can sound loud out of a short-barreled pistol and quiet out of a rifle.
To have quiet loads in any caliber without using a silencer/suppressor, the key is to have a subsonic load fired in a
(Excerpt) Read more at ammoland.com ...
Keep in mind that low velocity rounds increase the possibility of a squib load.
Readers are reminded to make sure bullets have left the barrel.
However, at velocities from about 600 fps to the speed of sound at about 1100 feet per second, bullet will reliably exit the muzzle.
When bullets do not exit, it is almost always a problem of a lack of powder in the cartridge, although, rarely, a contaminated powder charge will be the culprit.
I always thought bolt action .22 helps to keep noise down as well when compared to straight blowback. Maybe it was just that they mostly had longer barrels. How much noise comes out of blowback actions vs a locked breech?
Freegards
I shot a SBR AR-15 once. Wow, a real ear killer.
😉👌
This Ping List is for all news pertaining to infringes upon or victories for the 2nd Amendment.
FReepmail me if you want to be added to or deleted from this Ping List.
More 2nd Amendment related articles on FR's Bang List.
Would you happen to know of a .22 bolt gun that will reliably stabilize and shoot the Aguila 60grain subsonic load?
The Al Quaeda rats don’t hear the gunshot when they’re taken out by our sniper. All his friends standing nearby hear is the pink splatter landing on their uniforms.
I always enjoy shooting .357Sig at the range. No matter how many shots are going off around me, the first time I pulled the trigger it really turns people’s heads.
Manually operated firearms do reduce the noise level, mostly from action noise.
This is mentioned in the article.
No. However, you could get a barrel which has a twist rate of 1-7 or so for the 10-22, purchase a Ruger 77-22 bolt action .22 (now out of production) install the fast twist barrel, and have one that way.
Travis McGee on freerepublic has a 10-22 he put a fast twist barrel on, and reports he has had good results with it and the 60 grain Aguila rounds.
My experience is the 60 grain Aguila rounds work better from manually operated guns.
I put a 74 brake on one of my Draco’s just to make it obnoxiously loud. It was less an AK pistol and more like a flashbang launcher at that point. I shot it without ear pro for the full effect and HOLY CRAP that thing is just stupid loud. And fun.
I got like 20 AK flash hiders, brakes, compensators etc laying around and they’re all 1/2x28 so I can throw anything on anything, as far as all my AKs go. I do the same thing with optics and scopes for them too.
If you need a good flash suppressing comp I recommend the PWS FSC in whatever caliber you’re running, first gen if you can find one. S cond gen doesn’t have the prongs at the front anymore and they’re known to sometimes (rarely, once or twice per mag) to collect unburnt powder in vents near the tip and they CAN flash if the gas hits it just right. Other than that, it’s a superb como. That’s not a huge issue for me, just something to be aware of
Superb comp*
I just did sound tests and here are some of the results.
No Silencer
4” barrel pistol: ~116db. Best: Federal 22 Subsonic (115.6db).
16.5” barrel rifle: ~113db. Best: 105db, Aguila 60gr subsonic (105.6db).
With Silencer
4” barrel pistol: ~99db. Best: Federal 22 target (98.4db), Aguila 60 subsonic (99db).
16.5” barrel rifle: ~98db. Best: 105db, Aguila 60gr subsonic (93.4db)
Basically, all weapons and ammo seem to center on 116db unsuppressed, and 96db suppressed. The suppressor provided 20db reduction. Some suppressor do up to 30db, but most 22cal suppressors only do 20db.
These numbers are also similar to what I measured using various rifle combinations of 5.56mm, 300 Blackout, 6.8, and 300 winmag. The 300 winmag was 144db and suppressed at 116db using a 30db can.
Rifles do tend to be quieter than pistols, but only by 3db. 22LR is quieter than 9mm, but still audible at many hundreds of yards. A suppressed 22LR is quiet at about 200 yards.
Quiet is relative, but I use the metric that if a sentry can hear it, then it is not quiet enough. A suppressed 22 using a 20db suppressor is quiet only past 200 yards.
Also, the First Round Pop (FRP) of the silencer is important. It raises the noise by 10db compared to the second shot. The silencer I was using did not experience FRP except on high velocity rounds like the CCI Stinger. Subsonic rounds did not experience FRP at all.
Are you saying I can't believe Hollywood? I'm crushed!
There is a significant drop in barrel pressure and noise level as a barrel gets longer. A very nice study is available at the link EFFECTS OF BARREL LENGTH ON BORE PRESSURE, PROJECTILE VELOCITY and SOUND MEASUREMENT
Having reliable instrumentation and siting is an enormous problem in measuring sound levels of firearm reports.
It seems even instrumentation costing tens of thousands of dollars is problematic, because of differences in location of the instrument and orientation of the firearm.
3 db is reported to be a subjective noise reduction by half.
As to utility of suppressors, there are many situations where they have significant utility. In your example of a sentry, what is the background noise?
Is he located in the open, or in a forest?
Is there any wind?
A close friend told me of many combat uses of improvised/self-made suppressors. He said they had wonderful utility, simply in conserving hearing during use of M-16 rifles inside of buildings.
Gee, something like that would be exactly what I had in mind, I would never have known. THANKS for the tip!
That's gonna be my next project.
I have probably zapped more vermin with my Remington 581 22lr bolt action using CCI CB Longs, than anything else I own.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.