I have been chasing this a bit lately ordering a couple of barrels, one 6.5 CM and one 300 PRC. The general recommendations have been to keep it under 300,000 RPM to avoid bullets shedding jackrts. 9 to 8 t gain wist in the 30 Cal should be safe but the 6.5 is pushing it at 8 to 7. Ended up calling Bartlein to change to 8.25 to 7.25 as I kept worrying about it. The gain twist with 5R rifling is about as gentle rifling as is available in these barrels. I want to be able to shoot the heavy solids but not have the twist so fast regular bullets blow up so conventional will work too.
Litz gets into this in his books. If I am remembering correctly Nathan Foster might as well. It's been a bit since I read his stuff.
You can't really over spin a solid. Jacketed bullets run into two potential issues. The coming apart has been mentioned. The other is inconsistent jackets and the bullets getting thrown as they leave the barrel. The faster you spin the more exaggerated that can be. Modern match bullets that is minimal with the better jackets.
Litz gets into this in his books. If I am remembering correctly Nathan Foster might as well. It's been a bit since I read his stuff.
You can't really over spin a solid. Jacketed bullets run into two potential issues. The coming apart has been mentioned. The other is inconsistent jackets and the bullets getting thrown as they leave the barrel. The faster you spin the more exaggerated that can be. Modern match bullets that is minimal with the better jackets.