I reload and use coreloks in my .300 Wm and my 30-30 Marlin with great results.The Marlin is my sons and when We got it I didn't have a set of 30-30 dies. We were in a hurry to try out the rifle and bought a couple of boxes of Factory Remington ammo. The best we could shoot was 5-6" groups from a rest at 100. We were dissapointed. I bought a set of dies and using Rem brass, and Rem Corelok bullets I shrunk the groups to 1 1/2 " with a 100 fps increase in velocity. I find the bullets are great the ammo needs some work.IMHO