Back in the summer I got a new personal rifle for work. I went no thrills m4 colt with an aimpoint pro and added one of the new surefire DFs. I ran it at FOP3 and it was boringly accurate and reliable. The short rail kept proving to be annoying, and I tried an assortment of trips to get more comfortable but I always felt like I was chasing the muzzle with my hand so far back on the gun.
Because of overtime, I was able to build up this week. I got a new stock colt upper with a 16" barrel and took it to my local gun shop. The guys there are squared away and rapidly got me set up with a 15" BCM Mlock rail and some DD fixed front and back. I also tried out, but acquired elsewhere, an aimpoint comp m5 with the larue 660 mount to replace the Pro on my quest to be lighter.
At the end of the build they suggested I go with a muzzle brake instead of the stock A2 flash hider and give a hand stop a try. I went with a BCM Mod 0 comp and an Impact Weapons Components low profile hand stop.
I went to the range today to break it in before I qual with it and holy shit do those two items make a difference. The length of the rail with the handstop really let me lock the carbine into my shoulder and the muzzle brake made rise almost nothing shooting 62gr ammo. My double taps/follow up shots were (subjectively) faster and more accurate. Being able to guide the rifle into the reload position when I ran dry with the handstop was also subjectively faster for some reason, maybe because I could break my grip sooner.
The comp m5 is also a little piece of work in it's own rite. As small as it is and with the battery compartment high and right, I felt like my situational awareness and field of view was enhanced over the Pro or similar. This was my first time running lower 1/3 cowitness vs my usual absolute cowitness and I noticed a huge improvement in my ability to pick up the dot and make shots from various positions.
So, in short, BCM and handstops are good. Comp m5 is freaking amazing.