What rail is this? Looks old-school and don't recognize.

[ASH556]

I walked into work Saturday to see this lovely Colt 6933 upper sitting on the wall. It's not new as the tag says (mistake maybe?), but the price is right, BCG and CH included. I just don't recognize the rail and it has no markings I can find other than the "T's".

http://farm6.staticflickr.com/5521/12295976183_0be9014286_b.jpg (http://www.flickr.com/photos/87859750@N03/12295976183/)
Untitled (http://www.flickr.com/photos/87859750@N03/12295976183/) by ASH556 (http://www.flickr.com/people/87859750@N03/), on Flickr

[ASH556]

Well, looks like it's a CAA X6 rail...junk: http://www.opticsplanet.com/caa-picatinny-rail-aluminum-handguard-system-for-ar15-m16-6-rails.html

[MistWolf]

You could always buy the upper and sell the rail to someone on TOS! http://www.classicbattletech.com/forums/Smileys/alive/2funny.gif

[Col_Crocs]

^^yup... Looks to be sitting on the GI barrel nut and delta ring, not a proprietary one.

[ASH556]

Hmmmm...I put both of these uppers together for some local guys. The top one was a 6933 with an FSB shave now wearing an NSR 11. The subject upper could be pretty hot with a custom FSB cutout NSR rail like another member here did:

http://distilleryimage3.ak.instagram.com/67f8ce9c8b2311e38a02124717398e23_8.jpg
http://i1295.photobucket.com/albums/b628/2nd-Amendment/Bricksx2_zps50d10af9.jpg

[karmapolice]

do it and buy the other upper for me lol.