Yesterday I decided to run a few different 6x45 loads over a chronograph. My goal was to load some different powders I had on hand to get baseline pressure and velocities. I chose loads that I thought would be safe in my gun.

These loads were fired through an AR-15 built around a Midway AR Stoner 5R 20” barrel. None of the loads showed signs of excessive pressure and seem to have room for development. All were loaded to mag length, 2.260”. Mixed cases and Tula SR Magnum primers. All functioned perfectly in my gun.

Conditions were not great. Temp was 99 degrees. (HOT)

I only used two bullets. First was the Sierra 90 gr GK FMJBT. My goal was around 2,600 fps with this bullet. No problem.

1. 22.1 gr Alliant 1200-R, Avg velocity 2554 fps, ES 73.7
2. 24 gr Varget, Avg velocity 2486 fps , ES 38.1
3. 23.6 gr 8208 XBR, Average velocity 2622 fps, ES 34.7
4. 24 gr TAC, Average velocity 2591 fps, ES 9.4
5. 24 gr AR-Comp, Average velocity 2662 fps, ES 62

The low ES of the TAC load was a pleasant surprise. Think that will be the first powder I work with. It’s also a great powder for my 77 gr 5.56 loads.

I also fired a few rounds using the 55 gr Nosler Varmageddon. This bullet is fun and blows up anything it hits.

1. 26 gr 1200-R, Average Velocity 3277 fps, ES 12

Hope this is helpful.
_________________________
Cliff
USN Ret. FPD Ret.

Never underestimate the power of stupid people in large groups.