What barrel length for a pistol silencer?

[levsmith]

Hey everyone,

I have been looking into 22 pistols and found the Ruger mark III 22/45. I would like to buy it with a threaded barrel so that I have the option to add a silencer later on. I see on their website that the main threaded barrel version is a 4.5" barrel (model# 10150), but they just look to short to me. I have found that they do have a 5.5" threaded version (model# 10155) but it is not listed on the website. The 5.5" version looks alot better in my opinion and is what I think I want. Also should be a hair more accurate.

Now my question. I've heard that supersonic ammo works fine in pistols because the barrel isn't long enough to reach supersonic speed (hopefully i understand that right). Just wondering how long the barrel can be before it does reach supersonic speed. Would a 5.5" barrel still be short enough to use supersonic ammo with a silencer or would a 4.5" be a better choice? It just got me wondering since they don't advertise that version, that maybe there was a reason.

Thanks for any help

 

[Magoo]

The rule of thumb I heard "somewhere" was that a barrel 5 inches or less will keep most 22LR ammo subsonic. Maybe someone will come along that confirm or deny that with some actual evidence.

 

[rjrivero]

If you shoot standard velocity ammo, just about any barrel length is fine. If you're shooting the high velocity bulk stuff, then shorter is better. I have a S&W 2206 that has a 5" barrel and the high velocity bulk stuff is supersonic coming out of it.

 

[levsmith]

OK thanks for the replies guys. Sounds like the 4.5" would be the better choice. I would like to shoot bulk pack. Thanks again for the info. Glad I asked before I got the 5.5". But it will probably still be a little while before I buy it so I'm open to hear more replies.

 

[LiquidTension]

Running Federal bulk pack out of my 5.5" MkII I get some that go supersonic and some that stay subsonic. Obviously in winter you get more breaking the sound barrier than in summer. Wolf Match stays subsonic in rifles and pistols but it is more expensive.

 

[crazy-mp]

Most of the standard velocity stuff will stay subsonic, the hyper velocity stuff is hit or miss it just depends how hot it is. Its best to buy several different kinds of ammo and see what your gun likes the best. That's half the fun of owning a suppressor.