Re: Palma Brass
Unless I'm hunting in cold weather, the Palma brass is all I care to use. Using the 205m versus the 210 large I do find that loads are slightly slower but it's not bad. Extreme spreads are lower with the small primer. With H4895 and H4350 my extreme spreads are in single digits.
If you're blowing primers running the 215s, your loads are too hot. The Palma brass can help but it's still probably too hot. Have you tried a slower powder? What is your velocity and barrel length?
I'm getting 2550'sec with the 215s over 48.0 grains of H4350 and the 205m in the Palma case. Zero pressure signs. Even using large rifle cases and primers there is zero pressure signs. They're mild to say the least. You can get enough H4350 in a 308 case to cause over pressure with 215s. I'm at 2648 with the 200 hybrid and 2601 with the 210 ALR. All with 48.0 grains and the 205m primer.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.