Rifle consists of an Aero Precision M4E1 upper in 300 Blackout with a 10" barrel, and a 9" M-Lok handguard. The bolt carrier group came from BCM, and for now it has just the plain AR charging handle. The registered SBR lower is a plain old mil spec PSA lower... If I had it to do over again, I would have bought the Aero lower, but at the time I bought my 2 AR lowers, I was getting them "just because" and had no real plan for what to do with them. In all likelihood, the PSA lower is probably the same lower made on the same equipment, with different markings.
It has just the plain PSA lower parts kit, mil spec carbine buffer tube, and Hogue furniture. I got an H2 buffer for it since I read that it would be better for running suppressed. I went with the Bobro BUIS because I wasn't sure at the time what optic I would get, and I wanted the lowest profile sights I could get. I was going to get metal BUIS no matter what, so taking that into account, the extra cost of the Bobros wasn't horrible. I had planned on just running the irons for now, while I decided what to do for an optic, and then I came upon a deal on the Nikon M300 BLK 1-6 power scope, that was too good to pass up. Wouldn't necessarily have been my first choice in scopes at its regular price, but at less than 1/3 the regular price, I jumped on it. A nice scope deserves a nice mount, so I sprung for a Bobro quick detach mount.
The muzzle device is a 51T Blackout flash hider from AAC that fits my SDN-6 can. As I posted in other threads, upon initial assembly it had an alignment problem, so I sent the upper back to Aero, and they put a new barrel on it. It still had the problem when I got it back, so I dug deeper and found that either the barrel threads are too long, or the threaded portion of the flash hider is too short, because it bottomed on the muzzle instead of the shoulder. I put two .030" alignment shims under the FH and alignment is good now. Between all of that, it took me until yesterday to get it to the range.
Bad news first... It wouldn't run supersonic ammo reliably unsuppressed, with either the H2 or the carbine buffer... I got a number of failures to eject. With the can installed, it was fine with either buffer, so I put the H2 back in and left it there, and ran with the can for the rest of the day. I also didn't get to do much with subs, because the #$%&^ fire department showed up and made them close the entire range due to a gas leak in the area. By the time they confirmed the location of the leak and called the utility, I was running out of time and had to leave anyway.
On to the good news:
The Barnes black tip 110 grain hunting ammo, and the 120 grain UMC range/practice ammo both grouped at 1-1/4", and to about the same point of impact. I zeroed the scope for the 120 grain and am planning to use that for my primary supersonic load. The rest of the story with that ammo is it is actually loaded by Barnes with Barnes components, and then packaged in Remington UMC boxes. I've been buying it for $15/box on sale at Cabela's. I also tried some Hornady 110 grain v-max, but it was all over the paper at 100 yards.
I did get to fire a few subs. I shot a few rounds of the Hornady 208 grain, and the Remington 220 in the green and yellow boxes, both of which functioned OK and were extremely quiet. I found that the 3rd hash mark on the reticle (corresponds to 350 yards w/supers I think) was about right for the subs at 100 yards. I also have 3 boxes of the 220 grain UMC that I want to use up, but I haven't read much good about that ammo, and I wanted to put a few rounds of it unsuppressed through a target at closer range before sending it through the can, to make sure it doesn't tumble or anything. That was about the time the range officer ran in and called a range-wide cease fire, so I didn't get to do that. My plan also included moving down to the pistol range, setting up clays on the berm, and plinking at them with subs. But I didn't get to do that, either.
