Just initial thoughts on the precision AR setup in 6mm ARC, actually shot it about a week ago... been sick and getting over a cold/flu. Caveat being I only shot it at 31 yards for initial sight in and have only shot 30 rounds through it - forgot my bipod so had to shoot it prone off a backpack. So it was only a half serious attempt, mainly just wanted to get an initial zero. Will get better feel of accuracy once I get real time with bipod behind it and full serious attempt, but initial feel is uncertain about it right now - looks like it might be really ammo sensitive. Shot three different factory Hornady loads: 10 each of the 80gr ELD-VT V-Match, 105gr BTHP Hornady Black, and 108gr ELD Match.
Also, all shots were surpressed with my new surpressor which finally got the HUXWRX Hub adapter installed on from local gunshop (they even told me how difficult it was getting the factory direct thread adapter... which is why I brought it in as was starting to damage the half the lug holes even with it clamped in the adapter with a supporting heavy duty strap wrench, heating body end near Hub with torch, and using dry ice quickly on the hub adapter before trying to tap it off. Supposed to be 35lb-ft...can garuntee well over a couple hundred lbs F was needed to break the torque at least. Would have also been better if didn't use barrel nut cutout as the tool fastening system - some kind of flat would allowed for more secure tool attachment to the Hub adapter.)
So on to how it actually initially shoots. Used the 80gr to start first shots in the new rifle and after 4 shots got it really close to the X, shot 5 was just bit more of improvement,and shots 6-10 were no more touching adjustment - just see how it grouped. Gas block was fully opened (18 clicks) and brass ejection was at bare minimum around 4:30... shot really soft and noticed no gas in face at all. Zero function issues and chronoed all shots. 10 shot group was average of 2,894fps with STD DEV of 10.7fps, Spread of 36.5fps, min/max of 2878/2915fps. Grouped okay for halfway trying off a bag:
The 80gr load was as good as it got though, with the 105gr and 108gr loads things open way up and in a circle pattern:
10 shot group for the 105gr load was average of 2,663fps with STD DEV of 9.9fps, Spread of 34.6fps, min/max of 2648/2683fps. 10 shot group for the 108gr load was average of 2,658fps with STD DEV of 9.3fps, Spread of 27fps, min/max of 2642/2669fps. So not bad, but don't think those loads like it with the surpressor, looks like a nodal/harmonics thing. Ejection of brass about same but a little closer to 4:00 than 4:30 for both the 105gr and 108gr. Need to try without surpressor and see what it does and if it will even cycle - will need to play with buffer weight it looks like. With those results of the 105gr & 108gr and not having my bipod I wasn't going to waste any more time this trip on the 6mm ARC, so swapped over to my 300BLK since made some changes and wanted to see how it would do with my surpressor on it. A Little before and after:
Before
After
Main reason for rifle changes is because of now having night capability... all I'm going to say/show is below:
Surprisingly, the 300BLK rifle was still zeroed great, didn't have to touch a thing and was right on at 130 yards ringing small steel silloute plate (16x9). Had to try to miss... was right on and easy to hit. Bit more gas than the 6mm ARC, and ejecting right at 3:00. Just did a quick 5 shot group over the Garmin before having fun and the AAC 220grain I was using averaged @ 1041fps, STD DEV of 27.4fps, Spread of 75fps, min/max of 1010/1085fps. The way the firing impulse is, unsuported standing it's hard to do quick short strings of fire... could probably tune the gas down just a bit. Resting against the top bed of the truck though, incredibly easy to do a 4 shot rapid string and the plate go ding-ding-ding-ding... Oh yeah and the best part, no hearing protection required... it's like surpressing a subsonic .22LR... absolutely stupid quiet! Hearing the plate is louder than the shot. Ran two mags without hearing protection and two mags with... Really like that 300blk rifle and new surpressor! It's definitely quieter than the HUXWRX surpressors and a bit lighter as well. Really nice unit, only issue is the Hub adapter is REALLY on there so you need the right tools/method to be able to swap to whatever Hub adapater you need! Best thing for them to do is just not tighten down the hub adapters!