Long story short all I have right now is Fed210's. I have a 300 PRC on the way. I will be using h1000 but have limited supplies, so I don't want to waste supplies trying things out. I know it will "work" but don't want to waste powder on sub par performance. The goal is to confirm a solid load and get 50-80 loaded for hunting for the for seeable future. The 210's work great on my 6.5 PRC but that's with 59 gr not the 80+ I'll be using in my 300 PRC. What's your experience using large rifle primers in a magnum round?