Hi Folks, I was able to assemble my 6x45 upper last night and do a little shooting today. It is a standard profile 18" 1/9 twist barrel with a rifle length gas system. I built it on a Barrett upper I had in the safe with a MI 2nd generation handguard and low profile gas block. I had a couple of minor issues with the barrel. The barrel threads had to be cleaned up with a 1/2-28 die before I could screw on a flash suppressor. There was a substantial burr at the gas port in the bore. I knocked some of it down with a bore brush and figured the first round fired would get the rest.
How does it shoot? Not bad. My intention today was to check function, dial in my scope and start barrel break-in. I loaded 22 rounds with Sierra 70 grain HPBT match bullets over 26 grains of IMR 8208 at mag length. Functioning was fine. Only issue was the rounds were a touch long for the Magpul mags I was using and would hang up a little. I don't think it will be an issue with aluminum mags. Pressure seemed to be mild.
My last 5 round group was an RCH over 1 inch. The last 2 rounds I had came in at .8 inch. I think this will be a shooter.
Thanks Greg. The trigger is Armalite's 2 stage "Tactical Trigger". Nice break but the trigger pull is a bit heavy. A match trigger will be in the works.
I have pair of 3 LB Timney drop ins that are very nice. I use them on my PD and IPSC guns. Not real cheap but nice. Ritch uses some RRA types that he really likes that are not high dollar I have not tried one of those yet.
I also have the Giselle High Speed Match rigger in one lower that I am using all the time. Two stage with Stage # 2 let off at about 8 ounces. Around $280.00. This one has all the extra springs so I can shoot it as a Match Rifle, Dedicated Marksman or Service rifle. A couple of springs and fifteen minutes and you are GTG on the changeover.
The best firearm for self defense? Any loaded one will do.