@PB&J. what is your COL/Load data?
2.550" COAL
Lapua brass
Federal SRP
I float between Varget and H4895, I am shooting Varget at the moment. (Sorry, I won't give my charge weights as there is no "standard" chamber, too many variables).
The beauty of a custom is you can spec exactly what you want. I wanted an easy 3,000fps (opinions on realistic velocities varied) and this does it. There is more velocity in it, but it shoots extremely well at this speed and I don't need to push it to the ragged edge as I only shoot for fun.
The headspace wasn't cut to a crush fit (-003 to -.005) like most. It shares the same neck/shoulder location as .223rem so the initial firing was done jammed into the lands to be safe.
The neck length was also specced a bit longer than SAAMI because I wanted more neck support at that long COAL, but it will still hold on at the shorter neck length. I just let the cases grow over a few firing/sizings to get there.
It was borderline fitting in my MDT poly mags at that COAL, but I knew that going in and modified them accordingly. I also modified the feed lips a bit and profiled the feed ramp in the action to optimise the feeding of this load.
With such a small case, a few thou here and a few thou there yeilds bigger gains than it would in say a 300wm.
I only ever intended to shoot handloads through this rifle and thought if I am optimising, then I might as well optimise. It works extremely well.