Ranch - I found mine shot a fairly wide group when forming the cases with PP bullets. Once the cases had their shoulders formed, things started coming together nicely. So far, I've found my best load is as follows:
Jamison Brass, annealed before each loading
CCI BR2 primers
Goex FFg, 70 gr (weighed) dropped thru a 24" tube, lightly compressed when seating the 1/16" thick overpowder card
a 1/4" thick wad of SPG lube, topped with another 1/16" thick card
I top mine with a swaged 407 gr bullet, patched to bore diameter, dry wrapped, hand seated, unlubed
I have a CH-4D neck sizing die with bushings that lets me adjust how much tension I have on the bullet. I have a series of bushings in increments of 0.001".
The longest distance I've shot with this load is 200 yds, but at that distance, you could cover 5 shots with a quarter. I don't wipe between shots - I use a blow tube. 5 good, slow, deep breaths allows the next round to chamber with ease. I haven't experimented to see how many rounds I can shoot before I have to wipe, but so far I've shot 45 rounds in a match. After the rifle has been sitting a while and has cooled off, I just use the blow tube to get the fouling soft with about 8-10 breaths, and carry on as usual.
I've tried every granulation of Swiss & Goex with this exact config, and the Goex FFg was the winner. So far, that's the extent of my testing. Since my club only shoots out to 200 yds, I'm not feeling overly compelled to do much more. But I will. Eventually. If there's one thing we all have in common it's the inexplicable urge to tinker. LOL.
By the way - Very Nice Rifle!