Longest barrel length, but still sub-sonic?

[Alderleet]

This question has been bugging me for a few days. I'd like to make a 10/22 SBR, with a suppressor, but i want to shoot generic bulk box 22lr ammo.

The question i have is:

What is the longest length barrel you can use, but still keep the round subsonic? I'd like to retain accuracy, but i'm willing to sacrifice some, to make the suppressors job easier.

 

[Austan]

Re: Longest barrel length, but still sub-sonic?

I'm not entirely sure what you're asking. Do you want a long barrel or a SBR (short barreled rifle)?

Here are some numbers out of a 24" barrel. Link

Maybe that will help.

 

[frog5215]

Re: Longest barrel length, but still sub-sonic?

My 6" S&W 422 shoots Fed bulk supersonic, transsonic and subsonic.
Most feel 4 1/2" will be reliably subsonic with bulk HV. Maybe 5"

 

[buffybuster]

Re: Longest barrel length, but still sub-sonic?

With a 22lr, the velocity peaks somewhere between 16-22" (depending on type of rifling, bore condition, seal, etc). In long barrels, the bullet actually starts to slow down, as pressure has dropped and the bullet is coasting down the bore.

If you want HV ammo to be subsonic, probably looking at a 10-12" barrel.

 

[frog5215]

Re: Longest barrel length, but still sub-sonic?

Like I said, the .22 AR/10-22/pistol guys find anything longer than about 5" to be a problem. As for one long enough to let HV coast down to subsonic, I'm pretty sure even 28" isn't long enough. 10-12" will definitely give a crack.

 

[LoneWolfUSMC]

Re: Longest barrel length, but still sub-sonic?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Alderleet</div><div class="ubbcode-body">What is the longest length barrel you can use, but still keep the round subsonic? I'd like to retain accuracy, but i'm willing to sacrifice some, to make the suppressors job easier.
</div></div>

If you are running suppressed and want accuracy use SV or Match ammo.

HV is louder and less accurate even out of a suppressed pistol. I have run a couple different types of bulk HV through my P22/Outback. I prefer not to anymore.

If you want to shoot bulk HV ammo, then no so but know you will be less accurate and louder.

 

[SkaerE]

Re: Longest barrel length, but still sub-sonic?

im sure someone will correct me if im wrong but running bulk ammo through short barrel (to keep it from reaching supersonic) will really dirty up an integral can.

at least in my experience with the screw on type. seems way dirtier, i assumed it was unburnt powder residue or some similar byproduct

 

[Alderleet]

Re: Longest barrel length, but still sub-sonic?

it really doesnt matter about dirt. Its going to be a Silencerco Sparrow suppressor, mounted on a Ruger Charger.

I'm just trying to find the length just before a 22lr reaches supersonic.

So far, im thinking just a hidesertdog 4" threaded barrel and the can

 

[frog5215]

Re: Longest barrel length, but still sub-sonic?

So you'll SBR it and put it in a rifle stock?
4" ought to do it. That's why Walther's crappy little P-22 is so popular with suppressor fans, with only 3 1/2" barrel, they shoot nearly everything subsonic.

Most SV and Match ammo is subsonic out of barrels up to 18" in my somewhat limited experience. Was shooting Fed 714, SK Standard Plus, Eley Sport, Eley Practice, and Eley Match Semiauto today in my Compass Lake SPR, through the Spectre, along with some Fed AutoMatch, which is supersonic. Everything else was quiet.

Also cleaned the Spectre, after probably 500-800rd since the last cleaning. Probably a heaping tablespoon of grunge.

 

[Solothurn]

Re: Longest barrel length, but still sub-sonic?

In central Alabama...

Out of a 4 3/4" Ruger MK-II, all of the HV .22LR that I tried was supersonic.

My 4" Ruger 22/45 MK-III is subsonic with most, but not all HV ammo.

I want to suggest that you get your barrel threaded for the 22Sparrow O-ring. It really helps keep the silencer from loosening while shooting.

 

[Alderleet]

Re: Longest barrel length, but still sub-sonic?

it sounds like 4 is about as long as i can go.

thanks for your help

 

[jthyttin]

Re: Longest barrel length, but still sub-sonic?

I'd just shoot bulk SV. It may be a bit more expensive, but burns cleaner etc.