Regular pistol primers will start to flatten at about twenty~30k psi, dependant upon manufacturer and magnum versus standard. Thinking of a 9mm can operate as large as 35k psi for usual masses and approximately 38,500 psi for 9mm +P, there isn't any question . I purchased 1K for 45 Colt https://winchesterprimers35678.snack-blog.com/31790307/the-definitive-guide-to-federal-primers-210m