I received on Monday the Colt 901 AR15 upper adapter. This really lets me start to use the 901 in the modular capability I was really looking forward too when it was first announced. Don’t get me wrong, if the 901 was limited to only being a .308 AR I would still find it the best .308 AR for me, but it sure is nice to be able to use it with standard AR15 uppers too.
Since getting the 901, I have made a few changes. I dropped in a Geissele SSA trigger, replaced the stock with a CTR. I keep a Nightforce 2.5-10×24 scope on it, but sometimes I take that off and play around a bit with an Aimpoint PRO. For me, the CTR is a more comfortable and better stock for how I use the 901. The SSA is just a nice upgrade. The Nightforce makes it a nice package as the 2.5x setting is still reasonably fast up close, and 10x is enough magnification for me to do some good shooting, with out slowing me down or letting me fool my self into thinking I am running a pure precision rifle. One ergonomic change that made a bigger effect than I expected was adding Tango Down SCAR panels. The 901 quad rail is tall and narrow. I considered adding some rail panels to the side to help make the handguard feel a little more round. Normally I would use KAC rail panels as I have many of them laying around, but the 901 lacks the notches required for the KAC panels to lock into. So I picked up some TD SCAR panels and have found that I really like having them on the 901.
A friend shooting the 901 with an Aimpoint PRO in Wilcox mount.
Colt 901 lower with 5.45 upper. Using the 901 lower with standard AR15 uppers means I have to carry less stuff with when I go shooting.
When I shoot off the bench I have generally been using a Harris BRMS bipod. I have also been trying a Grippod on this rifle but I am not sure if it is right for this rifle. If you end up shooting off a hard surface, those slick feel of the grippod slide way too much when shooting .308.
Soon I will add an AMBI safety and another sling mount. I find I often use the left side mag release and the right side bolt catch, the ambi-safety will make the rifle fully ambidextrous.
My future goal is to register it as a Short Barreled Rifle so I can run a 10.5 inch 5.56 upper on that lower, and also have the 16in .308 upper. I really want to have a hard case that will contain the set of a 5.56 SBR upper and the standard 901 upper along with a few optics. That pair, combined with a small .30 can suppressor that could work on both uppers would do most everything I could want out of an AR.