My 300 norma improved which holds 12gr more than your 300sm with lapua brass barely does this. The 300sm case is in NO reference to a 300 rum. It has 16 grains less powder capacity and operates at 75k plus psi to get your velocities Rich. Your improved cases only warrent the velocity increases in smaller bores which represent overbore characteristics. I appreciate your work and engineering trials and tests. But you've just created stouter geometry to handle more psi by making the case stick to the chamber better. To achieve these super high velocities to small gain in powder space is because of BIG pressure. There's a reason you require rws, adg, lapua, peterson brass. Anything else cannot hold a primer after one firing.
I have 2 soon to be 3 of your designs, 25sst, 6.5 max and 7mm max. The sst has 70gr capacity in small bore, it'll go fast with normal psi, the 6.5 holds 77gr capacity in smaller bore, it'll go fast. The 7mm hold 78gr capacity and does NOTHING more than what a 7mag will do in adg brass. Load your cases to 65k psi and less, and the improvements will be minimal in the 7mm and bigger chambers. Sorry I just get tired of hearing these claims of my case gets this ridiculous speed sith tiny charge weight! That's cuz it's too good go be true, some you're loads are likey approaching 80k psi chamber pressure, and that sh!ts just plain stupid and dangerous.
Sorry rant over..........
