I have been struggling to get the performance I want from 17 MACH IV reloads. Custom rifle, Rem 788 action, cases formed from RP 223 brass. Using magnum SR primers to prevent blown primers. Good accuracy with N133 powder.
15 grains N133 3,300 fps; bolt rotates and cycles-ejects case. 16 grains N133 3500 fps; bolt rotates requires light tap with plastic hammer to cycle-eject case. 17 grains N133 3700 fps; bolt rotates requires slightly harder tap with plastic hammer to cycle-eject case.
Primers aren't flattened. I had a gunsmith inspect chamber for roughness that might create extraction issues. He didn't see anything to cause concern.
I would like to achieve speed around 3,700 fps without case ejection issues.
Anyone have any ideas??
15 grains N133 3,300 fps; bolt rotates and cycles-ejects case. 16 grains N133 3500 fps; bolt rotates requires light tap with plastic hammer to cycle-eject case. 17 grains N133 3700 fps; bolt rotates requires slightly harder tap with plastic hammer to cycle-eject case.
Primers aren't flattened. I had a gunsmith inspect chamber for roughness that might create extraction issues. He didn't see anything to cause concern.
I would like to achieve speed around 3,700 fps without case ejection issues.
Anyone have any ideas??