Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login

Site Notices
1/22/2020 12:12:56 PM
Posted: 8/27/2009 4:28:10 PM EST
I'm thinking of taking 6" of barrel off of my 24" DPMS 308 LR and making it an 18" length barrel. Will the performance and/or reliability change due to the rifle-length gas block location? I've already put a slash carbine buffer, spring, and SOPMOD stock on the rifle. I don't want to go with a new carbine length barrel and gas block because I have a rifle length DD rail on it already.
Link Posted: 8/28/2009 12:59:04 AM EST
I can't see any reason for reliability to suffer, although you might see a little less velocity if you shorten the barrel.
Link Posted: 8/28/2009 9:34:27 AM EST
My dealer ordered a 24" barreled lr308 for me and I wanted a shorter barrel. DPMS told my
dealer they would only shorten it to 20" for reliability reasons. I did not inquire as to what
problems would be encountered if it was made any shorter.
Link Posted: 8/28/2009 10:22:57 AM EST
An 18" tube with a rifle-length gas system doesn't give you much dwell time (the length of time between the bullet passing the gas port till leaving the muzzle, when the gas sytem is pressurized). You'd almost certainly have to open up the gas port to a larger diameter to compensate for the reduced dwell time as opposed to the 24" tube. I don't know what that diameter would be.
Link Posted: 9/17/2009 10:46:19 PM EST
you may need/most likely will have to open up the gas port.

a #44 drill bit is required for armalite 20" barrels. not sure about dpms. (the gas port locations differ slightly. the ar10 gas port is slightly further away from the receiver.)
Link Posted: 9/18/2009 9:00:02 AM EST
Thanks for the input. But, since posting this back in August, I have decided not to spend the time and money jacking with this barrel. I'll just start the project with a new shorter and lighter barrel.
Top Top