I've employed BR-two's in 7mm rem mags with good results, even in cold temps. But, that was with really large circumstance fill of H1000 and Reloder 26, and honestly I choose to use mag primers, they have not been detrimental to having constant velocities, so it takes away any stress https://griffingpqqm.ampedpages.com/details-fiction-and-federal-large-rifle-58735299