Rich,
I use winchester WLR in most of my guns. I just had a gun rebarreled and my gunsmith worked me up a load using 210m primers because i was in a pinch for time when i get the gun back. I ran out of 210m and had to hurry up and bye BR2 primers thinking that they would be close. Before i went to the match that weekend, i talked to a buddy that has been shooting the 1,000yd game for a long time. He told me he's always had problems with the BR2 primer's when he tried them. I went to the match and tried them. Out of 30 rounds, i had 9 rounds that the primers failed to light. I took the same box of primers the next week and loaded 50 rounds for practice. Not one failed. As long as i have been shooting WLR's i never had a problem. I load 2 6.5 x 284 guns and a 300wsm with them and they work fine. WLR's are a little hotter, not much more. On my 300wsm i worked 2 loads. 1st load 2906 fps, i had 16 for ES and 5.83 for SD. My 2nd load 2877fps, i had 14.38 ES and 6.32 for SD. I also have seen guy's shoot BR2's all season long and it did'nt seem that they had a problem.