The Winchester Large Pistol primers that I have say clearly on the carton they are for use in standard or magnum loads. Check your paclkaging for confirmation and be safe.
Yep, they say it on the box and I have used Winchesters with H110 in heavy .45 Colt "Ruger Only" loads and have had no issues with full combustion. Works great.
Dont use them in rp brass... or at all. If you do, please post pictures of the pits in your recoil plate. They ignite magnum loads of h110 just fine, but they dont hold up under pressure.
edfardos