m16a1 upper on ar lower

[joebowlin]

do you guys headspace these upper or do theyt usually work perfectly.

Good question. I would like to know this also.

What ammo have you found to work good with the 1:12 twist rate?

[DB2]

I use 55 grain, specifically xm193. I didn't check the head spacing when I put mine together. I did use all Colt parts(less lower & FC parts)though, since I wanted as close to an M16 as legally possible in Ca.. I haven't ever heard of anyone having head space issues on these uppers.


1:12 is good for 55 grain or less. Like I said I have heard some guys use 62 grain with good results, but I have not tried it. Anything heavier will tumble and loose acuracy.

[Lon Moer]

Of course, if you're really going to build a "retro" AR, then you need one of the various Retro lower's now available from NoDakSpud.
I just got my XM16E1 lower last week

[joebowlin]

I just got the upper receiver/barrel in the mail today. It is in really good condition. The rifling looks very good, only minor scuffs on the triangle handguard, and the receiver has only minor wear. Overall I am real happy with it.

On the rear sight, it flips 90 degrees and has another sight. What is this for? They appear to be the same size and in the same position.

On the right side of the rear sight, it has a round dial (i'm guessing for distance.?.?), it was set to 4.
After playing with it, it adjusts windage.

The door on the receiver, am I supposed to open it when I fire? Or will the pressure open it? Is it just there to keep dirt out in the field?

[Lon Moer]

On the rear sight, it flips 90 degrees and has another sight. What is this for? They appear to be the same size and in the same position.

They both have the same aperature, but one is higher than the other

On the right side of the rear sight, it has a round dial (i'm guessing for distance.?.?), it was set to 4.
After playing with it, it adjusts windage.

Yes, and the front sight post is for elevation.
Here's some zeroing methods

The door on the receiver, am I supposed to open it when I fire? Or will the pressure open it? Is it just there to keep dirt out in the field?

Yes. Keep it closed, the bolt carrier will open it.

[joebowlin]

I just bought this bolt carrier group:

https://rs533.securehostserver.com/~globalta/axami/shop.php?grd=360&prd=369

Any one have this?

[Lon Moer]

Denny at GTS is a good guy, always quality products.