375 Ruger IMR Green

[clearwater]

Had a chilly range day. -5 F. Chrono battery died for the last shots. It was good to get out tho and bright sun on the target.

Using 240 grain plain base, Brinell 15, had some consistent velocity results. 12 FPS spread over 6 shots with 11.5 grains IMR Green. 1188 fps average. 2.25" group that widened to 2.45" at 10 shots. Should be about the speed of sound in warmer temps.

Also 3 loads with some Unique (old batch from the 70's) for comparison. 13 grains. 2" group. 7 fps spread. Average 1233 fps.

Very fun to lob large bullets. Pretty happy so far. Should I be trying different velocities?

Really like my Chargemaster Link for these flake powders.

[Avenger442]

300 PRC
I just recently started casting for my Ruger 300 PRC. The 375 is the parent cartridge for this round. Have only been to the range one time with a NOE bullet measured average 228 grain. Trip was a disaster. None of the loads would stabilize and shots were all over the place. Most missing the 2' X 4' cardboard the target was on. Switching to a Lee bullet about the same weight but different profile. And as soon as I get some on paper I'm going to try some different powders. My twist rate is 1 in 9 and 230 grain is on the edge as far as being able to stabilize the bullet. May have to drop some weight. And get rid of these molds.

What twist rate is your 375?

[LeonardC]

I just checked the spec. sheet from my Hawkeye 375Ruger FTW. "Barrel Length: 22" Hammer Forged 1:12 Twist,"