Barrel Length and Suppressors

[SilverCat]

So I've been studying up on suppressors and everything that will come along with the subject in preparation to purchase one. I've never purchased a suppressor, but I'm aiming to start. I'd like to build an SBR .300 blackout rifle, and am debating a barrel length.
I recently read about a 9" .300 rifle a guy made, and it seems to work well. But I've heard that the minimum barrel length on a suppressed .223 was 10.5 inches or else it will wear out the suppressor, what about a .300 blackout??
What is the minimum barrel length that one could suppress on a .300??

Thanks

 

[Telekinesis]

Min barrel lengths are caliber specific. The reason a lot of companies won't warrant their .223 suppressors on barrels shorter than 10.5" is because the suppressor will essentially get sand blasted with unburied powder, which will eventually hurt the suppressor's performance.

The .300 Blk was designed from the ground up to be shot from short barrels without loosing much velocity (which means the powder burns relatively quickly), so you don't have a lot of extra powder in there to hurt the can. For example, my sub loads are using only 11gr of powder under 220gr SMKs. You will be fine with any barrel 8" or longer.

 

[SilverCat]

Thanks for the quick reply. I do believe that I have heard about the powder burning up. Something about .300 burning up in 8-9 inches. Thank you.

 

[PostalGlock'n]

As long as your shooting the subsonic loads, there's no problem but the 115gr - 125gr supersonics will, over time, erode the blast baffle.

The subsonic is very similar to a pistol round (180-230 @ 950-1000fps) so very little erosion.

 

[madFive]

Similar to this topic, does anyone know the minimum barrel length to suppress a 9mm? I have been looking for a threaded barrel to go on my Beretta PX4 Sub-Compact (3" barrel), and haven't had any luck yet. I've been wondering if the short barrel length is the reason, or if it should be ok to suppress and I need to just keep looking.

 

[wally]

I have been looking for a threaded barrel to go on my Beretta PX4 Sub-Compact (3" barrel), and haven't had any luck yet. I've been wondering if the short barrel length is the reason,

I think the reason is a "normal" suppressor is ~7-9" long so putting it on a sub-compact doesn't offer any advantage other than making most ammo subsonic because of the very short barrel and the disadvantage of a very front heavy gun with a very small grip. Without a significant demand you won't find threaded barrels as a catalog item.


There are some specialty suppressors that use wipes and have no provision for a recoil booster and keep the length in the 3-4" range. These would be cool on a sub-compact, but not all that useful because of the need to replace the wipes after not all that many rounds.

If this kind of "hollywood" setup appeals, look into the Thompson Machine "Posiden" line of suppressors.