Effects of a suppressor on accuracy

[jvik]

I was in a gun store the other day that specializes in class III stuff. They had some Ruger .22 pistols with barrels that acted as a suppressor - thus a class III Ruger .22. I was chatting with them about that sort of thing, wondering out loud why anyone would want a suppressor on a .22 and what effect it would have on accuracy. The reply was that they are very pleasant to shoot, not requiring any ear protection, and according to them, any firearm with a suppressor is inherently more accurate, since the suppressor "stabilizes the bullet."

Ok, the first part is reasonable - I lost most of my high frequency hearing to 22 caliber guns and farm machinery back in the late '50s - early '60s - before the effects of such was well publicized.

But what about the accuracy claim? I've no idea whether that might be true - I'd always assumed that a suppressor caused a decrease in accuracy.

 

[Alphazulu6]

Modern-day suppressors from all the research I have done does nothing to accuracy. It is like the "bloop-tubes" placed on competition rifles to extend sight radius for the competition small-bore shooter (only with chambers to trap the expanding gases).

The ONLY type of surpressor that has anything to do with the actual bullet and not just the gasses are the old-style slovic ones that use gasket flaps that the bullet must shoot through and touch. Even with this I am not sure how much the accuracy would be concerned but there are no dope bags regarding these old obsolete (and in some cases, possibly illegal) types.

 

[taliv]

i've often wondered about this because i've heard conflicting stories from respectable people. i think the theory is not that it "stabilizes the bullet" but that it helps prevent gasses behind the bullet from causing a lot of turbulence around the bullet immediately after leaving the barrel.

that seems to be a plausible theory. however, my personal experience with an AR15 is that it changes the POI but the groups are the same size with and without the can.

 

[Medusa]

Usually they do change the POI, but accuracy is mostly the same. But I've heard of some enhancements in accuracy because of trapping the gases in the suppressor, just like Taliv said. But they are not so common (maybe it's certain brand or model or certain gun?)

Otherwise they lessen the dB of the sound of expanding gases, and that POI change, but that's just about it.

 

[CDignition]

Go on over to Snipershide and ask there...

 

[Zak Smith]

While there are always things that can go wrong with complex systems, modern suppressors on already accurate bolt-action rifles do not harm accuracy. It seems like accuracy is increased, but that could be because many find it easier to shoot accurately with a can on.

 

[Correia]

I think Zak nails the biggest reason. I seem to shoot more accurately with a suppressed rifle also, and it is mostly because shooting is so much more pleasant.

 

[Beatnik]

Other thoughts:
Doesn't the suppressor add weight to the end? Maybe that's what stabilizes it.
Also, if you're going totally suppressed, isn't the firearm supposed to be shooting low charge ammo, so the bullet never goes supersonic? That would definitely affect accuracy....

 

[TX1911fan]

I shot a guys suppressed 92FS at the range the other day, and it was nice. A 9mm that sounded and recoiled less than a .22LR. It was very accurate, as well, except that the suppressor covered the front sight, so I had to guess where to put the round. Once I guess, however, it went where I pointed it. I'm afraid to get one because once I do I'll want a bunch more.

 

[Zak Smith]

Also, if you're going totally suppressed, isn't the firearm supposed to be shooting low charge ammo, so the bullet never goes supersonic?

No.

 

[taliv]

beatnik, i could be wrong, but my understanding is that the weight on the end is good and bad.

the good part is that adding weight reduces recoil
the first bad part is that it changes barrel harmonics and depending on how you've attached it, it can be different (i.e. wiggle a bit) from shot to shot, or from day to day as you remove and reattach it
the second bat part is that the weight way out there on the end may require an unusually stiff action

 

[Beatnik]

http://en.wikipedia.org/wiki/Suppressor#Ammunition_for_use_with_suppressors

 

[Zak Smith]

The overwhelming majority of rounds fired from suppressed centerfire rifles are normal full-power loads. Subsonic centerfire rifle loads are boutique items which are crippled ballistically and of limited use.

 

[Bubbles]

I have noticed a definite increase in accuracy with my suppressed rifles versus not using one. There are several reasons:

1) The suppressor reduces barrel whip, and

2) The suppressor reduces flinching (mine) from recoil and muzzle blast, especially in the larger calibers.

 

[Correia]

Also, if you're going totally suppressed, isn't the firearm supposed to be shooting low charge ammo, so the bullet never goes supersonic?

The supersonic crack of the bullet is really only devestating on the internet. In reality it sounds like CHUFF and is no big deal.

 

[PvtPyle]

It is a loud chuff at the shooters end. It still makes the sonic crack when it passes you at 90 degrees. I would submit though that if you hear the sonic crack but no shot, look and see who just got nailed and then seek cover quickly. But the sonic crack from a modern rifle round will not have any serious effect on you other than to scare the pee out of you (also contrary to internet and gunstore commando lore, even the highly powerful 50 BMG will not knock you down or kill you as it passes you. Will it Larry?)

 

[Correia]

No, but when the wall behind you begins to explode, apparently it is very exciting.

 

[jvik]

Beatnik, thanks for the pointer to the Wikipedia article. I never thought to look there.

Thanks to everyone for the information.

 

[VARifleman]

When a .22 LR goes supersonic, when fired out of my rifle (or anyone elses on my team), it's more than just a chuff. It's quite a bit louder, and much higher pitch.

 

[carnaby]

but that it helps prevent gasses behind the bullet from causing a lot of turbulence around the bullet immediately after leaving the barrel.

I don't think this is the case, since being supersonic, the bullet cannot be affected by any flow effects occurring behind it.

 

[Outlaws]

I don't think this is the case, since being supersonic, the bullet cannot be affected by any flow effects occurring behind it.

That would be true to some degree, but you have to remember that the stuff behind it is what is pushing the bullet out.

 

[carnaby]

Actually, Outlaws, I don't think that's true. I think that it's really the hands of very tiny fairies, kinda like the ones who made all those shoes, pushing the bullet out. That way it can go supersonic without being affected by the flow behind it, and then what I said above is completely true.

Hmmm, now that is interesting because you are, of course, correct. I wonder how far from the muzzle the bullet must be before it stops being influenced by the flow behind it???

 

[benEzra]

I don't think this is the case, since being supersonic, the bullet cannot be affected by any flow effects occurring behind it.

The gas stream exiting the barrel is more supersonic than the bullet. The instant the bullet exits the barrel, high-pressure gas is leaking furiously from the bullet-muzzle gap, and at the Reynolds numbers involved is a turbulent flow. The bullet continues to be blasted from the rear by supersonic gases for a few centimeters after muzzle exit, at least.

 

[carnaby]

It doesn't seem like the flow behind the bullet would remain supersonic for long, since it more or less free to expand once the bullet is outside the barrel. It'd be nice to see a visual from a CFD experiment to show exactly what is happening.

 

[taliv]

remember those health class videos of sneezes?