6.4 of Win572 1.25 OAL out of a 3.8 barrel, Hellcat RDP with a 20 pound spring, NEW RMI cases
low 1272 high 1286. occasionally 1250 1260. I think due to plus or minus .1 error rate of scale.
5.8 Barrel in a G34 KKM
1354 1381 using 24 pound spring and a shell shock case. Those cases will add 10 to 20fps over a brass case. Guns are worked hard at these speeds
Primers and head expansion good. Dont do this unless you understand the powder and have good case coverage. I would not use a once fired case. Always start low and work up, what works for one gun may not work in another. You’ll get a strong push, both guns are compensated and still using heavy springs. I would not in anything 3.5 or lower barrel.
Understand Winchester 572 powder, research the competition guys who have tried it out. Is OAL sensitive and temperature sensitive. Higher FPS lower temps.
To add, both barrels were throat reamed to accept that OAL, Nuke is a fat bullet, dont load this amount at shorter lengths.