Thanks for the response! I was shooting from my range’s Lead Sled and I double checked that my optic was torqued correctly and that I wasn’t jerking the trigger. I was using Norma .223 brass trimmed to 1.750″, bullets seated to 2.260″ (1.905″ using a bullet comparator), and CCI small rifle magnum primers (all I can get locally) so my ladder started below minimum. I started with 6-shot groups at 21.9gr and went up in .3 increments until I saw pressure signs at 24.2gr.
The best 3-shot clusters were 21.9gr at 0.632″ edge to edge at 100yds, 22.5gr at 0.685″, and 23.9gr at 1.049″. For full 6-shot groups only the best, 23.9gr at 2.171″ managed to go below 3″.
At this point I’m not sure if it’s the bullet not liking the powder or if my barrel (BA MK12 1/7 twist) just prefers lighter bullets. I’m trying to stick with extruded powders since the temperature in southern WI varies so wildly.
