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Gunsmithing AR vs Bolt action barrels

sentry1

Crayon Eater
Full Member
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Jul 7, 2012
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Madison, Alabama
What's the main difference? Can one take a Bartlein barrel intended for a bolt gun, stick on a barrel extension, drill a gas port and put it in an AR receiver?

Aside from obvious stuff like turning the barrel for the right width, etc... are there any differences?
 
Re: AR vs Bolt action barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sentry1</div><div class="ubbcode-body">What's the main difference? Can one take a Bartlein barrel intended for a bolt gun, stick on a barrel extension, drill a gas port and put it in an AR receiver? </div></div>
Given the dimensions are large enough in the proper places to allow it, Yes.



<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sentry1</div><div class="ubbcode-body">Aside from obvious stuff like turning the barrel for the right width, etc... are there any differences? </div></div>
No
 
Re: AR vs Bolt action barrels


The molecules that make up the steel in each are different. The ones in bolt action barrels move about less rapidly than those in the AR barrel steel. More rapidity levels out the barrel resonance to prevent dissonance with rapid fire vibrations resulting from the semi-automatic's action.
 
Re: AR vs Bolt action barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sentry1</div><div class="ubbcode-body">What's the main difference? Can one take a Bartlein barrel intended for a bolt gun, stick on a barrel extension, drill a gas port and put it in an AR receiver?

Aside from obvious stuff like turning the barrel for the right width, etc... are there any differences? </div></div>


Recently did that very thing. Bartlein M24's in 30 cal recontoured for an SR25. Did 13 of em actually.

Worked great!
 
Re: AR vs Bolt action barrels

I have been holding onto an old 223 varmint barrel off of a 700SA that I cannibalized for the action a while back. Planned on doing this very thing just to try it out. Glad to hear others have done this successfully.

Chad I was wondering if/how you located your gas port hole? Did you worry about putting it into a groove or just drill and shoot? I was thinking of working up a jig to locate my hole just for the challenge but if you did this and have ideas that your willing to share on it, it would make it a bit more interesting for me.
 
Re: AR vs Bolt action barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TGagnon</div><div class="ubbcode-body">I have been holding onto an old 223 varmint barrel off of a 700SA that I cannibalized for the action a while back. Planned on doing this very thing just to try it out. Glad to hear others have done this successfully.</div></div>

I made my first AR-15 barrel from a remington take-off barrel.
If you need help with dimensions, hit me up in a PM as I have ALL the info you could ever need to know about AR barrels...
 
Re: AR vs Bolt action barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">Recently did that very thing. Bartlein M24's in 30 cal recontoured for an SR25. Did 13 of em actually. Worked great! </div></div>
You're like a stripper. Making me want to spend money.
smile.gif
 
Re: AR vs Bolt action barrels

While its possible, it would cost ineffective, just buy a AR barrel ready to go.
 
Re: AR vs Bolt action barrels

If he has a take off barrel and the know how then it's pretty cost effective. Only a couple hours worth of work and only time spent if he has everything else he needs.
 
Re: AR vs Bolt action barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sentry1</div><div class="ubbcode-body">What's the main difference? Can one take a Bartlein barrel intended for a bolt gun, stick on a barrel extension, drill a gas port and put it in an AR receiver?

Aside from obvious stuff like turning the barrel for the right width, etc... are there any differences? </div></div>

Short answer, yes. GA Precision takes a modified Remington Varmint contour and turns them into their GAP-10 barrels. See the steps at the 4:20 min mark..

GAP-10 Video

Other companies take 1.050 straight blanks and turn them into AR-15's.

It is a lot of work to thread for the extension, breech cone, chamber, grind the gas block area, drill and ream the port and time the extension.
 
Re: AR vs Bolt action barrels

Try this on for size.

L-W is (simply) the world's largest producer of barrels, of all kinds, to all standards.

Saying they have a good idea about how to do it right is an understatement.

They work on a monthly production cycle. Once your payment clears, your barrel is in the next soonest month's production schedule.

Period.

I would suggest the 5.56 NATO chamber and a 1:8" twist for the least potential issues regarding ammunition. If you really want a MR/LR hammer, get the Match Varmint barrel.

Greg
 
Re: AR vs Bolt action barrels

In one of the AR Alternative Caliber classes I taught, all of my students started with unturned rifled blanks, and by thursday afternoon from monday morning, they had whittled out AR barrels, threaded for barrel extension, chambered to the headspace of their bolt, gas port drilled and muzzles threaded and crowned. Worked like a charm and the only malfunctions were not properly radiusing the back of the chamber to break the shoulder on two of the uppers. Little bit of polishing work and 100% pass on function.
It is a bit of work, and I have done the same for giggles with some takeoff barrels. Stick to the critical dimensions and have a blast!