I went out today to start load development. For reference, this is a tikka veil that was cut and threaded at 18" by class 3 machine. It has a total of about 60 rounds through it (I may be wasting my time starting any of this before giving the barrel a chance to speed up, which i certainly hope it does). Temperature today was about 50 degrees. Hornady lists 51.1-56.6 for H4831SC. I loaded (5 shots of each) 53-56 in .5 grain increments. I do not show any pressure signs on the brass and will continue to go up. Velocities were much lower than I had hoped with the 135s so far.
This was all done with new peterson brass.
53 grains was 2564 average, 53.5 was 2581.5, 54 was 2601.3, 54.5 was 2618.9, 55 was 2662.6, 55.5 was 2685.6 and 56 was 2704.2. I found it a little strange that i only averaged about 18 fps gain for 0.5 grain increment bumps (aside from the 43.7 jump from 54.5 to 55). Everything shot relatively well, most around .5-.75 and SD/ES was relatively good. These are all seated 25 thousands off the lands.
As stated I will continue to work up, but based on the velocities shown so far (unless the barrel speeds significantly in the next 100-150 rounds) I may pressure out before breaking 2800-2850.
Factory Hornady outfitter 130 grain was 2751.7 and grouped okay, quite well if I don't account for the flyer on the bottom. The shot above the group was my initial sighter.
I do have some H1000 that may be worth trying as well.
Also, ignore the "federal 205" on the primer, these were federal 210s, i just miswrote on every target.