02-06-2015, 08:00 PM
I'll be captain obvious here, but Alexander Arms of course uses the SAAMI reamer. I and another forum member were at a local range yesterday shooting 4 different 6.5 Grendel's.
With the 22" Lilja SAAMI chambered bull fluted barrel directly from Lilja/ Seekins billet set receiver build I did for him, I shot a rapid string at 100yds with a cadence like this:
One-and-a-two-and-a-three-and-a-four-and-a-five.
2nd through 5th rounds were into .3", 1st round opened the group to .6" @ 100yds. He shot a 5rd group with it slow-fire that was smaller than that. Winds were really heavy, with stiff enough gusts that I had to weigh down and anchor my soft cases (filled with mags and ammo already), and my spotting scope ocular cap blew off the tripod where I had it pinned.
My little lightweight 17.6" Grendel with the SAAMI chamber was able to print a .984" 5rd group in those winds. Most groups were no bigger than 1.5", when I let inconsistencies in my position factor in, which was hard to avoid with the wind blowing on me. AA cut that chamber for me in the 17.6" Lilja barrel. 3rd groups are easy to keep sub-MOA, but I like to see a larger picture of how I and the gun work together, and extend my ability to be consistent. If I shot from a rest with it, it would be easier to group with.
I will also say that after comparing a 7.62x39 bolt that was used for my friend's 6mm Grendel build, the .136" bolt face is the more sensible way to go because it allows you to have a more substantial extractor lip mass, as well as a large enough groove for the thicker Grendel rims.
With the 22" Lilja SAAMI chambered bull fluted barrel directly from Lilja/ Seekins billet set receiver build I did for him, I shot a rapid string at 100yds with a cadence like this:
One-and-a-two-and-a-three-and-a-four-and-a-five.
2nd through 5th rounds were into .3", 1st round opened the group to .6" @ 100yds. He shot a 5rd group with it slow-fire that was smaller than that. Winds were really heavy, with stiff enough gusts that I had to weigh down and anchor my soft cases (filled with mags and ammo already), and my spotting scope ocular cap blew off the tripod where I had it pinned.
My little lightweight 17.6" Grendel with the SAAMI chamber was able to print a .984" 5rd group in those winds. Most groups were no bigger than 1.5", when I let inconsistencies in my position factor in, which was hard to avoid with the wind blowing on me. AA cut that chamber for me in the 17.6" Lilja barrel. 3rd groups are easy to keep sub-MOA, but I like to see a larger picture of how I and the gun work together, and extend my ability to be consistent. If I shot from a rest with it, it would be easier to group with.
I will also say that after comparing a 7.62x39 bolt that was used for my friend's 6mm Grendel build, the .136" bolt face is the more sensible way to go because it allows you to have a more substantial extractor lip mass, as well as a large enough groove for the thicker Grendel rims.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com