25.0 Gr of 5744 works great with 311466 GC sized .309 in my M39's and Finn Tikka M91.
Same load with 200 Grain .308 R4 and .310 170 311291 Powder Coated with AL GC DID NOT.
Pierced primer with first shot in m39 with the 291 and blew the rim off the bolt face, locked up bolt.
R4 locked up other m39. I cleared inspected and shot 20 ea, 311466, as well as PPV 180 jacketed commercial, some 168 Nosler .308 and 174 SMK both with RL15.
Not sure what is going on. I pulled down all 9 rounds of 291 and one R4, powder was right on. Double charge overflows case.
Any thoughts on this? Thanks