New AR on the horizon

[Skinny Shooter]

Are you referring to Colt large pin Uppers?
Question #3 at this link addresses that issue: http://cheaperthandirt.com/blog/?page_id=96

Check out this link which has a link to what was known as "the chart".
It was a comparison chart of all major brands.
http://www.m4carbine.net/showthread.php?t=6642

The actual chart is offline but there are still a lot of details to read up on.
Brownell's has some AR gunsmithing videos on their website.

At this link are several versions in photos of "the chart".
https://www.google.com/search?hl=en&...mg.NlCMtSHXAFo

[muledeer]

I have a Bushmaster XM E2 (AR-15). I also have a Colt upper and it is interchangeable with the Bushmaster lower.
muledeer