pencil barrel for retro build

[trigga]

can't seem to find a 20" pencil barrel (M16A1) that is pre-drilled for the gas tube and taper pins. I found a few that had the FSB installed but either demanded a premium or out of stock. how hard is this to do or how much would it usually be to have this done by a gunsmith?

i would prefer something that is ready to go but if anything the green mountain barrel would be my first choice. there is a LGS that builds AR15s. i'll give them a call monday to see how much it would be...

here's the kit below. they do offer a barrel but again not predrilled and there isn't much on the specs of the barrel... what do you guys think? get this barrel instead of the green mountain? or any suggestions on where i can find one that is ready to go and need no machining. thanks.


http://www.e-sarcoinc.com/colt-m16a1-g-i-parts-kit-excellent.aspx

 

[briansmithwins]

can't seem to find a 20" pencil barrel (M16A1) that is pre-drilled for the gas tube and taper pins. I found a few that had the FSB installed but either demanded a premium or out of stock. how hard is this to do or how much would it usually be to have this done by a gunsmith?

You can't find them because that's not how AR system barrels are usually made. The general process is to attach the barrel extension to the un-chamber reamed barrel, then use the barrel extension to set the depth to finish ream the chamber to the correct headspace depth and hardchrome if desired. The barrel would then have the gas port drilled and the FSB installed to match the gas port location. Barrel nut, spring, and handguard retainer would also be installed.

Then the barrel and FSB are drilled at the same time in a jig. The taper pin holes reamed, and the taper pins installed. A manufacturer would normally never cut the notches in the barrel and then drill the FSB, and then try to get them to line up.

Too much time to do it that way and too much scrap would be generated.

With a clamp on FSB or gas block you just line the gas port up with the hole in the FSB and screw it down.

BSW

 

[MachIVshooter]

What BSW said.

Also, remember that if you're doing a retro build, you need an A1/A2 FSB. 90%+ of the FSBs on the market (including those pre-installed on barrels) are F-marked; they will be too tall for an A1 rear sight.

 

[Zach S]

F marked FSBs are only .040" taller, shouldn't be an issue considering the post is over .250" tall.

Double Star makes both the A1 (.625") and A2 (.750") front sight bases that are NOT F marked. I just bought one of the A1s from Brownells.

 

[trigga]

after much research i've come down to this kit... i think i'm going to order it tomorrow. main thing is it comes with the barrel installed and saw pix of someone's recent build on AR15.com. looks good. does anyone know if this is the correct contour/profile? doesn't say but it looks right. i emailed them a few days ago about it but no response. will give them a call before ordering tomorrow.

http://ak-builder.com/index.php?dispatch=products.view&product_id=30665
http://www.ar15.com/forums/t_3_123/...ro__kit_arrived.html&page=1&anc=bottom#bottom

 

[trigga]

akbuilder (Lonnie) just got back to me this morning at around 8 AM and yes everything is correct on the barrel. order placed and awaiting... now all i need is a fire control group... will post pix when assembled.