How difficult to build AR Upper reciever?

kjm · October 16, 2002, 01:29 PM

I have the lower, I have an upper, but I want to build another upper for my lower. I would like to use a shorter barrel. What is the legal length barrel I can use (post-ban)?

Will I need any really special tools? Can I build it myself cheaper or should I just order it from BM and be done with it?

The only reason I think I might get away cheaper is that I don't need the removable handguard, bolt carrier group, or anything that I don't already own. I just need the barrel, reciever, handguards and such. I wouldn't mind using an M4 barrel, but I am not sure yet. I just want to know if this is a feasible project?

Thank you in advance!

kjm

johnwill · October 16, 2002, 02:01 PM

Well, you need at least a 16" barrel to be legal, though that can be a combination of barrel and permanently attached compensator if you desire. FWIW, I wouldn't be swapping bolts & carriers between uppers, keep them with the upper they started with. This isn't always an issue, but it's sometimes a problem, and certainly a good practice...

James K · October 16, 2002, 02:54 PM

Swapping bolts could mean headspace problems. I would just build a complete upper and swap it off when you want with a minimum fuss.

Jim

john kilgore · October 17, 2002, 11:13 AM

I wouldn't bother to build myself. I called M&A parts from an ad in Shotgun news. They assembled what I wanted from parts and it was less than what I could buy the parts for separately from them. It shoots great. Accuracy is 1/2" @ 100yds.
It was a 20"match barrel (heavy) w/.750" foward of gas block. It has cylindrical forend and picatinny gas block and flat-top reciever. It also has bolt assembly, so all I have to do is swap tops. Total cost was about $350.00 shipped in 2000.

Rocklobster · October 17, 2002, 07:29 PM

Yep, you can build it better, cheaper. 16" inch barrel, minimum- no threading, no bayo lug on post-bans. The only thing that really makes a difference, headspacing-wise, is the bolt. You'll need a barrel nut wrench. Combo tool is best investment- allows you to remove/install the barrel, remove/install the buffer tube. Costs about 20 bucks.

Building it yourself's half the fun!

October 16, 2002, 01:29 PM	#1
kjm Senior Member Join Date: December 24, 1999 Location: College Station, Texas Posts: 1,871	How difficult to build AR Upper reciever? I have the lower, I have an upper, but I want to build another upper for my lower. I would like to use a shorter barrel. What is the legal length barrel I can use (post-ban)? Will I need any really special tools? Can I build it myself cheaper or should I just order it from BM and be done with it? The only reason I think I might get away cheaper is that I don't need the removable handguard, bolt carrier group, or anything that I don't already own. I just need the barrel, reciever, handguards and such. I wouldn't mind using an M4 barrel, but I am not sure yet. I just want to know if this is a feasible project? Thank you in advance! kjm __________________ COME AND TAKE IT!!!

October 16, 2002, 02:01 PM	#2
johnwill Senior Member Join Date: April 6, 2000 Location: PA Posts: 3,451	Well, you need at least a 16" barrel to be legal, though that can be a combination of barrel and permanently attached compensator if you desire. FWIW, I wouldn't be swapping bolts & carriers between uppers, keep them with the upper they started with. This isn't always an issue, but it's sometimes a problem, and certainly a good practice... __________________ I collect old pistols, got any?

October 17, 2002, 11:13 AM	#4
john kilgore Senior Member Join Date: August 27, 2002 Location: east georgia Posts: 125	I wouldn't bother to build myself. I called M&A parts from an ad in Shotgun news. They assembled what I wanted from parts and it was less than what I could buy the parts for separately from them. It shoots great. Accuracy is 1/2" @ 100yds. It was a 20"match barrel (heavy) w/.750" foward of gas block. It has cylindrical forend and picatinny gas block and flat-top reciever. It also has bolt assembly, so all I have to do is swap tops. Total cost was about $350.00 shipped in 2000. __________________ "There is no such thing as a second place winner in a gunfight" Bill Jordan

October 16, 2002, 02:54 PM	#3
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Swapping bolts could mean headspace problems. I would just build a complete upper and swap it off when you want with a minimum fuss. Jim

October 17, 2002, 07:29 PM	#5
Rocklobster Senior Member Join Date: October 11, 2001 Location: Georgia Posts: 188	Yep, you can build it better, cheaper. 16" inch barrel, minimum- no threading, no bayo lug on post-bans. The only thing that really makes a difference, headspacing-wise, is the bolt. You'll need a barrel nut wrench. Combo tool is best investment- allows you to remove/install the barrel, remove/install the buffer tube. Costs about 20 bucks. Building it yourself's half the fun!