I think the Lower pressure has to do with the greater case volume? What is the difference in case volume? Does the blown out 338 case have a close capacity to the HH case?
What is the capacity of the 338/375 case?
Well here's my capacity results (to base of neck of fired case:)
375 H&H (Fed Nickel) = 80.5 gr RL15
.375-338 (RP Nickel) = 75.7 gr RL 15
6.3% difference
I used Fed 210's also. I don't think you need a magnum cap for the likes of RL15, 4064 and Varget.
My practical max loads for lead core bullets are:
270 gr / 71.0 gr RL 15 / 2,675 fps / 21" bbl
300 gr / 66.0 gr RL 15 / 2,500 fps / 21" bbl
MM
