For a while I have been waiting for Colt to a announce a ultra-reliable ultra-high capacity magazine that will accompany the Colt Infantry Automatic Rifle. One of the requirements for the Marine IAR is a ultra-high capacity magazine.

At the Pakistan IDEAS-2008 expo an M16/M203 was on display with a MWG 90 Rounder High Capacity Magazine, sitting directly above a Colt IAR poster (Photo by skybolt @ Defence.pk).

The tan colored weapon on the poster is the Colt IAR. Click to expand.

I think it would be safe to assume that Colt is going with the MWG 90.

MWG 90 Rounder High Capacity Magazine

If you look closely at the first image it appears that the MWG 90 magazine is attached to the M16 upper receiver. Something is attached to the receiver which extends towards the magazine. Anyone know what this is? It does not appear visible on MWG promotional photos, such as this one:

Colt may have customized the MWG 90 to increase reliability/durability.