I necked up a 6.5 PRC to 7mm in a SA Archimedes with a 28" barrel. My first test loads used 52.5 to 57.0 of N-165 in .5gr intervals producing this graph.
I loaded up 10 more using old 168 VLDs I had going from 55.0 to 59.5 of N-165. I haven't fired those yet but I don't think I'm going to make the last few due to pressure, they're pretty compressed. So, here's the question: I need more speed out of the 166 ATips with less case volume so, do I go faster powder? If so, how much faster? I have some 4831SC that I'm going to try out, or should I look at going into the N-550 to RL-17 range? I guess I'm not understanding sufficiently the relationship between case volume, burn rate, and velocity
I loaded up 10 more using old 168 VLDs I had going from 55.0 to 59.5 of N-165. I haven't fired those yet but I don't think I'm going to make the last few due to pressure, they're pretty compressed. So, here's the question: I need more speed out of the 166 ATips with less case volume so, do I go faster powder? If so, how much faster? I have some 4831SC that I'm going to try out, or should I look at going into the N-550 to RL-17 range? I guess I'm not understanding sufficiently the relationship between case volume, burn rate, and velocity