06-19-2019, 10:16 PM
Cowin8579 Wrote:Hello gentlemen. I bought one of the 18" green mountain monster barrels and matching bolt. A friend of mine who shoots competitively installed it in a palmetto upper. I believe he installed it correctly.
I work at an indoor range that maxes out at 25 yards. I initially sighted in the grendel with a non parallax adjustable scope and it was challenging with fuzzy crosshairs. Right away the wolf ammo I was using was shooting a rather wide group, but I didn't take that as an issue due to previous experience with wolf.
I used a standard break in process similar to the Army designated marksman method, clean every shot for 5 shots, and then every 3 shots etc. Using Seal 1 and a bore snake.
Then I went to a 100 yard range and setup a lead sled. I then shot federal fusion and hornady black eld. The wind was gusting, it wasn't an ideal shooting day. For me at that time the fusion and hornady black both shot over 3 MOA. Due to the challenges of that range day, I did not take pictures of the groupings which would have been helpful to you.
I switched the upper to a 5.56 that I've hunted with for years, and shot my best sub inch group ever with Gorilla 77 grain SMK. Shot a few more loadings and it performed well.
My friend who installed the barrel (Matt Trout) offered to test it for me. His groups were way better than mine, with the Hornady black getting the closest to 1 inch MOA. He recommended I try more loads, and to try reloading etc. I do not reload.
Do you folks recommend any other premium loadings to try that you would eventually hunt with? I see Barnes and Alexander arms have some very premium rounds, I suspect hornady SST will group like the black, and Sellier and Bellot make an FMJ? Any other recommendations, or should I grab another barrel?
I have been hunting for 20 years, and hoped this new setup would be amazing.
1moa is good with over the counter ammo and a budget barrel.
Your friend shoot that, means you are most of the problem with the 3moa groups you fired.
Do you have a flinch? Did the increased recoil of the grendel compared too 556 feel more noticable?
You could try the AA and PF ammo that's loaded with match type bullets or maybe the federal 130 hybrid load.
I think you just need a lil time with it too get better adjusted and comfortable with the new round is most of the issue.
Could be your technique when holding the rifle needs some work as well.
Your competitive shooter friend should beable to help with a few tips.
My best friend is a heck of a marksman with a bolt action, but when I built his first grendel ar he had bad group's as well. Takes a certain technique too shot the ar good, more so when you increase the felt recoil over the 22cal.
Hope this helps sir.