2 Total Newb questions.... hand guard, and Bolt catchs.

[motorwerks]

OK so I am like a bunch totally new to the .308 platform and I just bought my first lower (its not even here yet because I live in CA and we have a stupid 10 day waiting period.) and I had an AR15 parts kit worth of parts left over from 5 or 6 other builds. Anyhow I ordered the Pivot pin and Takedown pin from Brownells and they are here. My Tactical Machine lower came with its own bolt catch pin so I am covered there, but what I am most curious about is.....

1. Can I use AR15 hand guard if I use a .308 delta ring assembly and the front little dinger (cant for the life of me remember what its called right now). I'm also kind of wondering if Ill be able to use the MOE hand guard ???

2. Will a .223 lower's bolt catch work in a .308 lower? I cant seem to get an honest answer from anyone. I know DPMS has a different part number but I have seen a handful of ".308" parts layouts that look like this one....

and have the only parts listed as "Exclusive" as the 3 pins.

[motorwerks]

poop figured out the bolt catch question, guess Ill be ordering one of those when I get paid.

http://308ar.com/forum/index.php/topic,690.msg4663.html#msg4663

[SWshooter]

Don't believe your hand guards will work either as the 308's use a larger diameter delta ring (barrel nut). Also, there are at least two different barrel threads and two different barrel extensions. Generally things are either DPMS or Knights armament compatible. That includes upper and lower receivers. Before you start a build you have to decide which way your going and stick with it. Your upper receiver is your most critical part, make sure it, and the buffer tube, bolt carrier group, buffer, buffer spring, barrel, and barrel extension are all compatible. They must work properly together or you will never have a reliable rifle.

[motorwerks]

I did a little more reading around and I think the Delta ring/Barrel nuts use the same Wrench from AR15 to .308 variant.

[SWshooter]

An AR-15 barrel wrench won't fit a 308 AR, the 308 barrel nut is bigger in diameter. The DPMS and KAC are different and there is at least one and maybe two others. IMSHUR can tell you all about barrel nut wrenches ;D

[survivalshop]

The std . barrel nut wrenches are for DPMS or Armilite type barrel nuts. There is a wrench out there that has both wrench ends to accommodate ether one .

But , as said above , when you get into free float hand guards , they open a whole new can of worms for wrenches.

I have heard of some using the Magpul MOE hand guards with some modifications to it , but no personal experience with it .

The AR 15/16 bolt stop will work ,but the one for the 308 has a larger foot to accommodate the larger 308 bolt .

You will also notice the different spring location for the take down pin. Some thread that hole for a plug & cut down the spring or you can cut it a little & be careful putting your pistol grip on .

Why does no one make one for the 308's ? (They put or mold the hole in it for the safety detent ! )

[motorwerks]

Yeah I have been threading every AR15 lower I build for years now for a 4-40 set screw to hold the take down pin in place. I think my lower even comes with that. Ill get to see it again this weekend when I get to pick it up.