Cut a 20" barrel down to 18"?

[jrob300]

Sorry in advance guys. Long time bolt-gun guy... dabbling in the dizzying world of gas guns.

I have a 16" 1:9 that I kinda wanted to upgrade to an 18" 1:8 or 1:7.7, but can't find a thing. May have a line on a 20" SS fluted heavy barrel that I figured I could just cut down to 18" and re-thread, but the question of gas block location and port dia. comes up.

I have no idea what I need. I'll be shooting MK262 clone ammo FWIW.

Any help would be appreciated.

John

 

[Ghogs Nightmare]

Re: Cut a 20" barrel down to 18"?

If its already at 20" I would venture to say it has a rifle
length tube on it.
.
I had my 24" cut down to 18" and it works fine shoots well so can be done no worries.
.
I didn't do the measuring but to my knowledge the smith used the
same parts that were on it. So i'd say choice is yours if you prefer rifle vs mid length tube.

 

[Pusher591]

Re: Cut a 20" barrel down to 18"?

If it's a rifle length gas system you will be fine cutting to 18.5".

 

[mstephenson51]

Re: Cut a 20" barrel down to 18"?

before you buy, check what the gas tube length is on the barrel vs the gun you want to put it on. to my understanding, there are only 4 standard lengths; pistol, carbine, mid, and rifle. match the length of the gun its going into so you dont have to buy more parts. ;0)

but yeah, just have a smith cut it down and rethread. gotta time the threads right for whatever you are puting on, sometimes it matters.

 

[jrob300]

Re: Cut a 20" barrel down to 18"?

The 20" is a rifle length... I figured I'd have to get a new gas tube anyway as the 18 I wanted (but is not in stock anywhere... duh

) is mid-length and my 16 is carbine length. But the "cut and thread" got me thinking... last time I had this done it was like $150. Arghhh...

Maybe just wait until 18's show up again and get what I really want. There's really no fire drill. Current barrel knocks holes in stuff just fine.

John

 

[ORD]

Re: Cut a 20" barrel down to 18"?

The only hiccup with cutting down ANY fluted barrel is that with hacking 2" off of it (to go from 20" to 18"), you may get into the fluting. Not a huge deal (aside from looking weird/FUGLY), unless the flutes are deep enough to potentially interfere with having the barrel rethreaded once it is cut down. Just something to think about/measure up before you go that route.

Aside from that, I run rifle-length gas systems on 18" tubes with no problems including running everything from 52gr to 77gr projectiles without missing a beat.

As for the cost...an AR barrel cut/crown/thread job can be had for significantly less than $150. See here: http://www.adcofirearms.com/shopservices/shop_.cfm?code=1

Steve and his crew will take good care of you. (I feel like a broken record tonight...I think this is the third thread I've mentioned Steve/ADCO in in just the last 30 min.)!!

Also, if you REALLY have to have your 20" cut down and you want a mid-length or intermediate length gas port, they'll take care of that issue for you too for not much more $$.

Good luck!

 

[rcmigpilot]

Re: Cut a 20" barrel down to 18"?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jrob300</div><div class="ubbcode-body">The 20" is a rifle length... I figured I'd have to get a new gas tube anyway as the 18 I wanted (but is not in stock anywhere... duh

) is mid-length and my 16 is carbine length. But the "cut and thread" got me thinking... last time I had this done it was like $150. Arghhh...

Maybe just wait until 18's show up again and get what I really want. There's really no fire drill. Current barrel knocks holes in stuff just fine.

John </div></div>

18" barrels come in, and work well with both mid and rifle gas so there's no reason to reconfigure the gas system. On the plus side, rifle length gas tubes are one of the few AR parts you can actually get right now. If it were me, I'd go for the $65 plus shipping and have ADCO cut, recrown and thread the 20" and go shoot. The way things are right now there's no telling when anything AR is going to be readily available again.