The WLR should be okay. Where you are, the temperature differential winter to summer won't matter. On heavy loads, with slow powders, in Montana in late November...cold, repeat damn cold, the standard primers I was using would give a "bap,Boom", with a low strike on target. Bad mistake. On big cases with slow powder in cold temps...stick with mag primers or the WLR. The WLR primers have a longer flame front for ignition of the Winchester Ball Powders. Just my experience.