Rebarreling an AR-15

Fatelvis · January 1, 2002, 02:44 PM

I`m pretty mechanically inclined, and "up" on guns, but I dont do much gunsmithing. I want to swap my stock Armalite bbl, with a freefloated, stainless match one. It`s for Highpower,(I`m making the switch from my M1A) Should I attempt to rebarrel it myself? If so, any helpful hints? What is the best "how- to" manual that you know of? As always, thanks guys.

George Stringer · January 2, 2002, 08:25 AM

If you feel comfortable doing it yourself and have the gages and knowledge to set the headspace correctly then by all means do it yourself. But if you're in doubt then I'd recommend having it done. George

Abe Normal · January 3, 2002, 09:36 PM

You'll need not only to have the headspace checked when you’re finished, you'll need to buy several dedicated tools.

1. A barrel nut wrench and a torque wrench that'll allow you to torque to 35 lbs. ft.
2. An upper receiver vise block/clamp.
3. A strap wrench, if you go with the screw on tube type forward grip.
4. (I'd also recommend you have on hand) a extra roll pin or 2 for the gas tube and a extra gas tube. As they sometimes don't come out of the old gas block in one piece, if they have been in there for many hundreds of rounds.

If you have any other questions drop me an e-mail.

Keith J · January 4, 2002, 10:11 AM

The art of a scratch rebarreling job on an AR is quite complex but installing a new barrel assembly on a receiver is quite easy.

A torque wrench isn't absolutely required as the torque value is a minimum torque listed. You have to line the nut up with the gas tube hole and many times at 35 ft*lbs you will be 1/2 a notch off. The only proper solution is to back off, relube and go at it again, seating the barrel extension into the slightly softer aluminum receiver.

Make sure the threads are well lubed (I use dry moly in lieu of grease to keep dirt accumulation down) and a bit of Loktite on the extension/receiver interface will improve the fit. This is very critical for accuracy with a tight sling. Be warned, disassembly will be difficult unless yo spray a release agent (dry moly) on the receiver. The Loktite is just for shimming, not adhesion.

Get the receiver blocks for clamping the receiver, not barrel. Avoid the 3-pin wrenches as they are nearly useless for disassembly and frequently break. They are OK for getting 35 ft*lbs but little more.

If you bought a name-brand barrel with a new bolt, you can ignore the headspacing game. There is nothing you can do anyway as far as adjustment since the assembly is already timed.

Fatelvis · January 4, 2002, 07:14 PM

Thanks alot guys, doesnt sound that complex. D you recommend any how-to books?

**4V50 Gary** · January 5, 2002, 11:38 AM

Get the USMC Armorer's manual. They're about $5 at a gunshow. ar15.com use to have instructions online and they're pretty helpful (and a good alternative if you don't want to spend the money).

BTW, when my uncle bought an "axle shaft" for a barrel (it was a DPMS 1 1/8" diameter barrel), my barrel blocks wouldn't fit (in the best Gomer Pyle Surprise! Surprise). We made barrel blocks from a piece of oak. Measure the outside diameter and then drill the block with a bit that fits the O.D. Cut the block of wood in half on a tablesaw and voila! Instant barrel blocks that don't cost $20.

January 1, 2002, 02:44 PM	#1
Fatelvis Senior Member Join Date: June 10, 2001 Location: Lockport, IL Posts: 490	Rebarreling an AR-15 I`m pretty mechanically inclined, and "up" on guns, but I dont do much gunsmithing. I want to swap my stock Armalite bbl, with a freefloated, stainless match one. It`s for Highpower,(I`m making the switch from my M1A) Should I attempt to rebarrel it myself? If so, any helpful hints? What is the best "how- to" manual that you know of? As always, thanks guys.

January 3, 2002, 09:36 PM	#3
Abe Normal Senior Member Join Date: May 23, 1999 Location: Eastern North Carolina Posts: 104	You'll need not only to have the headspace checked when you’re finished, you'll need to buy several dedicated tools. 1. A barrel nut wrench and a torque wrench that'll allow you to torque to 35 lbs. ft. 2. An upper receiver vise block/clamp. 3. A strap wrench, if you go with the screw on tube type forward grip. 4. (I'd also recommend you have on hand) a extra roll pin or 2 for the gas tube and a extra gas tube. As they sometimes don't come out of the old gas block in one piece, if they have been in there for many hundreds of rounds. If you have any other questions drop me an e-mail. __________________ Abe If everyone thought like me, I'd be a damn fool to think any different!

January 4, 2002, 10:11 AM	#4
Keith J Senior Member Join Date: December 15, 2000 Posts: 469	Headspace? The art of a scratch rebarreling job on an AR is quite complex but installing a new barrel assembly on a receiver is quite easy. A torque wrench isn't absolutely required as the torque value is a minimum torque listed. You have to line the nut up with the gas tube hole and many times at 35 ftlbs you will be 1/2 a notch off. The only proper solution is to back off, relube and go at it again, seating the barrel extension into the slightly softer aluminum receiver. Make sure the threads are well lubed (I use dry moly in lieu of grease to keep dirt accumulation down) and a bit of Loktite on the extension/receiver interface will improve the fit. This is very critical for accuracy with a tight sling. Be warned, disassembly will be difficult unless yo spray a release agent (dry moly) on the receiver. The Loktite is just for shimming, not adhesion. Get the receiver blocks for clamping the receiver, not barrel. Avoid the 3-pin wrenches as they are nearly useless for disassembly and frequently break. They are OK for getting 35 ftlbs but little more. If you bought a name-brand barrel with a new bolt, you can ignore the headspacing game. There is nothing you can do anyway as far as adjustment since the assembly is already timed.

January 5, 2002, 11:38 AM	#6
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,832	Get the USMC Armorer's manual. They're about $5 at a gunshow. ar15.com use to have instructions online and they're pretty helpful (and a good alternative if you don't want to spend the money). BTW, when my uncle bought an "axle shaft" for a barrel (it was a DPMS 1 1/8" diameter barrel), my barrel blocks wouldn't fit (in the best Gomer Pyle Surprise! Surprise). We made barrel blocks from a piece of oak. Measure the outside diameter and then drill the block with a bit that fits the O.D. Cut the block of wood in half on a tablesaw and voila! Instant barrel blocks that don't cost $20. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

January 2, 2002, 08:25 AM	#2
George Stringer Staff Alumnus Join Date: October 12, 1998 Location: Earlington KY Posts: 2,299	If you feel comfortable doing it yourself and have the gages and knowledge to set the headspace correctly then by all means do it yourself. But if you're in doubt then I'd recommend having it done. George

January 4, 2002, 07:14 PM	#5
Fatelvis Senior Member Join Date: June 10, 2001 Location: Lockport, IL Posts: 490	Thanks alot guys, doesnt sound that complex. D you recommend any how-to books?