Took my new Bushmaster ACR to the range for the first time today to get the sights zeroed and do some function testing. Weather was overcast and cold, with no wind to speak of. Fired 272 rounds of Federal XM193 55gr ball, Black Hills 60gr soft-point, and PPU 75gr Match HP with no malfunctions of any kind.
• The Troy Micro flip-up sights proved a bit difficult to get dialed in; I could put together decent groups using the small aperture, but switching to the large aperture introduced a vertical POI shift of several inches, even at 50 yards. The apertures are supposed to be same-plane, so either my rear sight is out of spec, or I'm doing something different/wrong when I'm aiming through the large aperture. More testing (with someone who's more of a rifleman than me on the trigger) will be required to get the issue sorted out.
• The Primary Arms red dot in the LaRue HK mount works pretty well, but the large emitter located at approximately 4:30 partially obscures the sight picture, which proved quite distracting. The Aimpoint Micro's emitter, while located in the same position, is much smaller and does not obstruct the field of view. I have one on the way, and the PA Micro will be up for sale shortly.
• The trigger pull is heavy, but has a very positive break and reset that allows good accuracy work to be done. I did feel hampered during rapid fire, though, and trigger finger fatigue set in quickly. Basically I've become spoiled by the triggers I've got in my ARs (RRA 2-stage match, and standard trigger groups with JP spring kits), so I'll definitely be doing something to improve the ACR. A Spike's Battle Trigger set, perhaps?
• Despite having a barrel with a 1x9 twist rate, my ACR did not seem to show much difference in group size among the three loads I tested, at either 50 or 100 yards. The groups below were shot with iron sights at a distance of 50 yards. With my (bad) eyes and the stock trigger, this is about as good as I can be expected to do.
Iron-sight groups at 100 yards were an embarrassment, but that's me not the gun! With the red dot mounted, the gun showed that it was capable of shooting within the dot size (4") at 100 with all loads tested.
• Recoil on the ACR feels more like my AKs than it does my ARs; "abrupt" would be a good adjective to describe it. Not uncomfortable at all, just different.
• Gun-forumites whine about the ACR's weight, but the real problem is its weight distribution. The gun is rather nose-heavy, which makes manipulations, repeated "ready-up" drills, and holding the gun on target for long periods of time more challenging. This can be addressed in two ways - "grow stronger" to quote a line from The 13th Warrior, and/or have the barrel shortened and reprofiled to remove some ounces from the front of the gun.
• The fixed stock works OK, but is not all that comfortable. The cheekweld surface is a bit boxy and hard on the face, compared to the sloping surfaces of the VLTOR and ACS, or even the CTR/MOE and standard M4 stocks. I also don't care for the uber-thick rubber recoil pad. Length of pull is right at 12.5" which is OK for shooting from the bench and running in just a T-shirt and jacket as I did today, but I worry about how it will work out when wearing gear, armor and the works. Hopefully my folding telestock will show up soon...
• The right-side selector issue was only a minor one for me; nowhere near a "deal breaker". I used Mr. Dremel to lightly round off the bottom edges on both sides (did not change the length at all), and now it feels pretty much just like an ambi selector on my AR – I know it's there, but it does not cause any discomfort.
In closing - I like how the gun shoots, the ambi controls and control layout, super-smooth action, and reliability. I don't like the unbalanced weight distribution, the heavy trigger, or the fixed stock (though it's usable for now). Jury is still out on the sights, both iron and electronic.
I did discover that the ACR/Micro combo, with the iron sights folded down, lends itself to i-Kam video better than most of my AR platforms with the larger Aimpoints.
YouTube - 20110314_003236.AVI
Once the gun is in its "final" configuration (need the Aimpoint and folding telestock) and I've had a chance to run it more extensively under more dynamic conditions, I will post an update. Might not be for awhile, though; beginning in April, I am planning to spend six months doing the lion's share of my shooting with my AK platforms, culminating with the STRIKE Tactical AK course in September.
More news as events warrant. Stay tuned!
ETA - I forgot to weigh in on the inevitable SCAR-vs.-ACR debate! Now that I have fired both, I can say with confidence that despite its shortcomings, the ACR whups the SCAR's butt handily. YMMV, but on this forum, it probably doesn't.