22LR barrel length to be sub sonic?

[par0thead151]

I am having my ruger 22/45 mark III 22LR's (pistol) barrel threaded, and i have read that if it is around 3" in length that the round will not have over 1000 FPS velocity and thus not need subsonic ammo when shooting with my can. is this true?
if so, is the 3" length accurate?
i shoot value packs from walmart so they are already light on the FPS side.
thanks

[mpmarty]

Not a good idea IMHO.
Keep the six inch or whatever barrel length you have and use cartridges designed for sub sonic work. Among other problems, a three inch barrel probably won't be enough to burn all the powder and you'll fill the silencer with junk you'd rather not have in it.

I once had a high standard silenced pistol and it was a work of art. Unfortunately I had to turn it back in when I was done playing with it.

[Willbird]

I did my mark III at 4" and it is OK with the Remington golden bullets bulk pack, but it is a bit snappish in cold weather with the federal bulk pack which is much nicer ammo. IMHO 3.5" would probably be about perfect. I shoot the federal all the time in hot weather and never get a sonic crack. It seems to be just as accurate as any other Ruger pistol I have had.

Bill

[303Guy]

Is that to say six inches is enough to produce supersonic velocity? (I plan on building a silenced rifle with a piece of barrel off-cut and a long silencer to make up the required length).

[par0thead151]

im not too worried about the powder harming the suppressor. it is made of stainless steel, and i am able to take it apart. also have a ultra sonic cleaner to help clean it.

[yondering]

Six inches will definitely produce supersonic velocities with the "cheap" [smilie=1: bulk pack ammo. 4" is about right.

On my suppressed Buckmark, I used a 5.5" threaded TacSol barrel for about a year. If I used the right ammo, it was mostly subsonic, but still a little snappy. Then Winchester changed the load on their bulk HP ammo, so it was no longer subsonic in my barrel. I recently went back to the original stainless barrel, and had it cut to 4" and threaded. Wow! Huge difference in sound, it's much quieter now and is subsonic with everything I've tried. (Haven't tried that hypervelocity stuff, but no reason to.)

No reason to settle for buying subsonic ammo, especially now when ammo is hard to find. CCI Subsonic is too expensive for a fun toy like a suppressed 22 pistol, and the PMC and Aguila subsonics won't cycle the action of my Buckmark or my Mk I.

par0thead151, what suppressor do you have, the Quest? Mine is the Outback II, I've put about 4K rounds through it and am pretty happy so far.

[par0thead151]

i am building my own(following all the ATF rules and regs of course, still waiting for their OK to start cutting the stainless steel) so until i get the GO ahead from the bat boys, i will work on my barrel.
the design will be a solid unit, much like most 22 LR suppressors. just a wimple wave design with a outer shell that is a snug fit. all one piece, so the baffels them self are one piece and thread directly onto the barrel.

[yondering]

Sounds interesting. Post some pics when you're done. I assume you are a member of silencertalk.com?

[par0thead151]

actually im not. i will have to check out that site.
thanks

[Willbird]

Not a good idea IMHO.
Keep the six inch or whatever barrel length you have and use cartridges designed for sub sonic work. Among other problems, a three inch barrel probably won't be enough to burn all the powder and you'll fill the silencer with junk you'd rather not have in it.

I once had a high standard silenced pistol and it was a work of art. Unfortunately I had to turn it back in when I was done playing with it.

All of the integral supressor pistols on the market today use a ported and or shortened barrel to do the same thing we are talking about. I have never noticed powder residue in my can, lead and bullet lubricant yes, powder no.

Bill

[Cap'n Morgan]

[QUOTE=par0thead151;612836]
the design will be a solid unit, much like most 22 LR suppressors. just a wimple wave design with a outer shell that is a snug fit. all one piece, so the baffels them self are one piece and thread directly onto the barrel.[/QUOTE

Something like this? A 1-1/8 x 6" 22LR suppressor. Simple, but efficient.

http://lh4.ggpht.com/_H70RUN_TQNw/Sl3tLAUOqkI/AAAAAAAAB-0/9NOHPuF3Oso/s800/IMG_0796.JPG

[yondering]

That looks nice. How well does it work?

[par0thead151]

exactly like that!

[Cap'n Morgan]

That looks nice. How well does it work?

I never run any test, but I have tried a whole bunch of different designs and sizes, and this seems to be the optimum size for a 22LR. In fact, the internals doesn't matter all the much with low pressure rounds. All you need is a sufficient volume for the gases to expand and the pressure to drop.