Newish barrel

[Robocop1051]

So, I've had this old Colt 5.56 barrel sitting in a drawer for quite a while. Nothing spectacular, just a 16" carbine, but it is a LW .625 pencil profile. I took it off a Colt 6520, and replaced it with a LW 14.5" middy.

I recently decided to start moving on my "pistol" build. Now instead of a new barrel, I found a guy who'll cut this Colt bbl down to size for me. I always hated that short barrels were med/hvy profiles. I'm going to take this old barrel down to 10.3" and bask in the excellence of its lightweight.

I've seen some pretty light pistol/SBR builds. I can't wait to see how this one turns out. I have an $1100 order on Brownells saved for a later date. I think the last part I'm waiting on is the release of the KAC URX4 rail system.

[blue109]

Awesome idea. Only thing I wonder about is the value of that barrel to a colt fanatic? Any chance you might be better off selling it and buying a new one with money to spare?

My 3lb dissy pig barrel is being turned down to .625 as we speak :). Can't wait to compare it to the dissy I built for my father in law. Should be able to drop at least a lb I'd think.

Edited July 25, 2013 by blue109

[FaRKle!]

You'll most likely need your gas port re-sized.

[Robocop1051]

You'll most likely need your gas port re-sized.

It shouldn't be by much. The military had been cutting 16" barrels down for YEARS. The Commando and XM177 are both chopped 16" barrels. Daniel Defense has been making their Mk18 with a 10.3" barrel and carbine gas for a long time too. I'll see if I can find the measurements for that gas port and compare it to my Colt. I'll also call the barrel guy and hear what he has to say. If he has to open it up, I'm ok with that too.

[FaRKle!]

From what I could find, the stock M4a1 gas port is 0.052" and the 10.3" MK18 is 0.07".

 

You'll definitely want an H2 buffer.

Edited July 27, 2013 by FaRKle!

[Robocop1051]

I can go all the way to .09 and then add a tungsten buffer.