Here is a unique Colt upper receiver assembly that I recently picked up. This upper receiver assembly has one of the uncommon Colt Defense labeled Troy rails.
This upper receiver was assembled at some point in 2016 (based on barrel date).
Here is a short video showing more of the rail. I will do a detailed post on this upper receiver at a later time.
The Colt AR-15 Resource 
Is that really long enough for a bayonet? Doesn’t look like it.
LikeLiked by 1 person
No, you could not mount a bayonet on this upper receiver.
LikeLike