Went out this morning to fire the very first shots through my brand new rifle. Tried to stay conservative but still worked up close to my expected velocities with the Hornady 75 and 88 gr. ELD's with IMR4895, RL-15 and H4350.
Showing powder change/velocity, avg. of three shots.
75 grain ELD
IMR4895 - trying for 3200 fps
31.0 / 2971 fps
32.0 / 3052
33.0 / 3126
33.5 / 3192 - bolt lift was decidedly sticky at this point. 4895 gave great groups and while it's nigh perfect for 55 grain bullets is a bit too quick for these heavier bullets.
RL-15 - also trying for 3200 fps
31.0 / 2885
32.0 / 3021
33.0 / 3099
33.5 / 3151 - think I will try going to 34.0, although groups at each level weren't quite as good as with IMR4895.
H4350 - hoping to hit 3250 or maybe 3300 fps with this one.
33.0 / 2763
34.0 / 2927
35.0 / 3014 - going to take this to 36.0 grains, maybe 36.5. Groups are as good as with 4895 but the burn rate of 4350 is much better suited to this application.
88 grain ELD - going for 2900 fps and only tried H4350 with this bullet weight
32.0 / 2722 fps
33.0 / 2799
34.0 / 2890
34.5 / ?? my chronograph battery died on me so I didn't get a reading but would extrapolate velocity around 2935 fps. Bolt lift still fine.
Started all bullets at .010" and they are showing a two and one pattern. Hardly noticeable at lower velocity with the three shot groups still staying at or just over 1/2", but the 88 gr. ELD really gets tossed out there with two shots close or even touching and the third out 2" or more. Going to seat everything at .030" to see if that cleans up this tendency and go to four shot groups at my target velocities to get a statistically better sample.
The really good news is that I took a road trip this afternoon to the next town over and scored 7 pounds of RL-17, two one pounders and a five pounder. Going to load up another pressure series with both bullets and hit the range again tomorrow morning - with a fresh chronograph battery.
