Hi, have a 350 in a ar15, 16" barrel. Been working on loads, and maybe the power to use is cfe black. Cci 450 primers. I swag down 358 bullets to 356, to get spire point bullets with higher bc. This will extend your range. I have had 150 so going 2500 fps so far, and 180 going 2350fps. Round acts like it's very accurate so far out to 250 yards. The trick is to run heavier bullets to get higher bc, to get more range.