08-12-2020, 01:12 PM
The above video illustrates the finer points and details from my range trip - for those of you here that just want the straight dish on data and highlights, read below:
Environmental Info:
86 degrees / 74% humidity / 12 mph wind at shooter 6 o'clock / 795 ft elevation / Sunny
Rifle details:
Proof Research Stainless Steel 18" barrel, 1-7.5x twist, Rifle +1 gas system, LaRue MBT 2 stage flat trigger, Leupold 8.5-25x56mm scope
Ammo used:
Hornady Black 105gr BTHP
Magazines tested and observations:
ASC Stoner 25 round 6.5 Grendel magazine - fresh out the retail packaging and into the rifle, downloaded to 23 rounds to avoid max magazine pressure which ordinarily creates a few issues from my previous use of them in Grendel. The mag inserts and drops freely, is of decent build quality, has a clearly marked follower "6.5 ASC". Unfortunately, as is the case with many of my previous ASC mags for Grendel, they just do not run well straight out of the package. And today was no exception, couldn't get a round to strip and feed.
UNIMAG - 24 round wonder-mag - these were developed within the last 10 years, the intent was to carry one mag for a multitude of calibers due to a special patented follower and mag design. The magazine did not insert easily or drop free from the rifle. The follow is not specially marked and loading style is critical in order to get these to function properly, press rounds straight down with two fingers (even pressure). I shot 6 rounds with the UNIMAG and they stripped and cycled fine. Cost and reliability concerns should be noted if pursuing this magazine further.
C-Products Dura Mag - A 20 round magazine design, which is usually the amount of rounds I load into Grendel magazines, give or take 3 rounds based on magazine functionality. The magazine inserts and drops freely from the mag well. Shot about 20 rounds with it and no stoppages. Looks to be of decent build quality and the price is right at under $20 bucks a mag. I will use these in my 6 ARC going forward.
Function of the firearm:
I was extremely pleased by the recoil being so soft yet the rifle smartly cycles and snaps up that top round from fully loaded magazines and gets it into the chamber without any issue. The Proof CamGAS system appeared to be spot on in terms of gas needed to cycle the 105 grain factory Hornady load. All brass was found within a foot spread, 4-5 feet back at the 4:30 position from the shooter.
The barrel did not seem to be effected by heat soak, shots were consistent with point of aim, the weight and balance is slightly forward of the mag release with a full size suppressor added to the mix.
Velocity data:
A Caldwell Chronograph was placed 10 feet from the muzzle and I called out the velocity on video and transferred the reading to my shooting log book when I got back to the house. A couple of rounds were well off the pace, no real explanation for this.
Zeroing and function testing: 2633 / 2626 / 2637 FPS
Group 1: 2619 / 2644 / 2642 / 2634 / 2644 FPS
Group 2: 2643 / 2653 / 2636 / 2633 / 2610 FPS
Group 3: 2649 / 2535 / 2535 / 2630 / 2628 FPS
Brass marks from shooting:
The primers all looked normal, no flat spots or cratering, and there were little to no ejector marks/swipes on the base of the cases. Pretty ordinary looking brass.
Groupings - 5 shot groups:
I had the rifle on a seated sturdy bench, bagged front and rear, view through the scope was comfortable and repeatable. On this given day the best group was .673" and the largest was 1.4" with multiple shots touching each other throughout the groups.
I would estimate that the load is capable of 1.25" groupings from my rifle and that is acceptable for my purposes whether that be plinking at the range or hunting medium to large hogs with it.
Overall thoughts:
After months of waiting to get this build assembled and to the range, I was very disappointed to experience the stuck bullets and powder dumping when extracting cartridges.
My initial thoughts to shoot through the Hornady Black ammo to harvest the brass for reloading is still the primary objective, it just doesn't pay to keep any of this 105 grain Hornady Black on the shelf until things get further sorted out.
Other than that - I did appreciate that the ASC mags didn't let me down, I would say 9 out of 10 mags don't ever run right for me straight out of the package - I've come to accept it and do my tweaks and once they are dialed in they run fine. But for new to the caliber shooters this is going to be an issue for them.