AT-X range report: just back from second trip out and I’m calling load development done. Did the recommended barrel break in per AI’s manual and used factory Hornady match 108gr ELD-M. Effortless to get zeroed but I expected that. The last 10 round group wasn’t spectacular but right under an inch with that Ammo. Moved on to my old rifles match load of 105gr Berger handloads. The AT-X didn’t like them as much but they kept the same zero as the 108gr factory Ammo which was cool. Speeds were about 140fps slower with my handloaded 105’s than with my other rifle which has the same length barrel but a Proof. Fired (38) total rounds between those two then started my load test of (5) groups of 5-shots with Peterson LRP brass, CCI 200’s, Berger 109gr Hybrid LR, and H4350 between 40.4-41.6gr.
Some groups in the 1/2” range, most were about 3/4”. After putting the data in a spreadsheet I noticed the lower end between 40.4-40.7 gr was a huge flat node that was obviously even bigger than that, but the SD/ES were a little higher than I wanted. Decided to hit the center of that node and work the seating depth to see if it would improve. Went with an initial target of 2.800 COAL and worked 0.006” up and down then again to cover as much ground as I felt it needed.
End result, so far the gun and barrel has (88) rounds. Many 0.50” groups, and the mirage was insane today for whatever reason so I’m honestly surprised it did that. A lot of SD’s in the 10 fps range and landed on gold at group #4 at 2958 FPS avg, 3.9SD and 9ES. I’ll take that to the races anywhere and it’ll save me a little barrel life running it a tad slower. That same load picked up 20fps from yesterday and even the hornady 108’s are up 20-30fps. I’m pretty sure it’s done speeding up now though, gonna load a few hundred and hit the barricades.
And got lucky with the MDT Black Friday sale so I’ve got a CKYE pod on the way to take advantage of the crazy low center of gravity this thing has.
Last two pictures are a 10-shot with Hornady 108gr ELD-M. And shooting a (3) shot group standing off a barricade at 100yds (circled) and removing/reinstalling the barrel, firing one round, then repeating for another round, for a total of a 5-shot group standing off a barricade with barrel removed twice at 100yds. Needless to say I’m happy