I've used BR-2's in 7mm rem mags with achievements, even in cold temps. But, which was with quite high case fill of H1000 and Reloder 26, and honestly I choose to use mag primers, they have not been detrimental to having consistent velocities, so it will take absent any worry https://shanezgtfr.worldblogged.com/37510672/the-2-minute-rule-for-schrotzünder-209