Rifle is a Grendel Sniper, 28" barrel, though mine is topped with a Nightforce NXS 5.5-22:
Fewer than 30 rounds downrange, but looking for a good 600 yard load.
It wasn't real happy with Amax's, though sub MOA at 100 yards when loaded over 29 grains of TAC.
I tried Sierra 107's over XBR 29 grains, and got very similar groups, less than an inch, but not quite what I was hoping for.
Then I moved to Sierra 107's over 28.5 grains of 8208 XBR, a completely new load and powder for me.
First group was around .50 MOA, loaded at 2.270. For a barrel with 20 rounds down it, I wasn't unhappy with that.
This is the second group, loaded at 2.260.
Though its hard to tell, (to me it looks like 4, not 5) but it is 5 shots in that group.
That's a group or .2155 inches, (.4795 - .264).
That was the last 5 rounds I had with me.
After 30 rounds, it was time to clean the new barrel anyway.
I don't have a working Chrono right now, and my efforts to borrow one for the trip was unsuccessful. Extrapolating the IMR data, I think the load is running at around 2650 FPS, which is just a VERY rough idea.
I'll hopefully be able to chrono this load in about 3 weeks, I have Boomershoot and then a son's wedding taking up the next few weekends.
PS. I eventually got this load chronoed, and it shot at 2785 with an ES of 15 from my 28" barrel.
Fewer than 30 rounds downrange, but looking for a good 600 yard load.
It wasn't real happy with Amax's, though sub MOA at 100 yards when loaded over 29 grains of TAC.
I tried Sierra 107's over XBR 29 grains, and got very similar groups, less than an inch, but not quite what I was hoping for.
Then I moved to Sierra 107's over 28.5 grains of 8208 XBR, a completely new load and powder for me.
First group was around .50 MOA, loaded at 2.270. For a barrel with 20 rounds down it, I wasn't unhappy with that.
This is the second group, loaded at 2.260.
Though its hard to tell, (to me it looks like 4, not 5) but it is 5 shots in that group.
That's a group or .2155 inches, (.4795 - .264).
That was the last 5 rounds I had with me.
After 30 rounds, it was time to clean the new barrel anyway.
I don't have a working Chrono right now, and my efforts to borrow one for the trip was unsuccessful. Extrapolating the IMR data, I think the load is running at around 2650 FPS, which is just a VERY rough idea.
I'll hopefully be able to chrono this load in about 3 weeks, I have Boomershoot and then a son's wedding taking up the next few weekends.
PS. I eventually got this load chronoed, and it shot at 2785 with an ES of 15 from my 28" barrel.
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