Sounds like it's time to buy a reloading setup. If you've already got the brass, a small setup for not much money would get you set up good enough to do some decent reloads for the 300 H&H. I could help you from there on out, as I've got a couple of 300 H&H's and handload for both of them, but you'd have to have the setup to do it first. Even a less expensive Lee Anniversary kit would get you most of the way, especially if all you're looking to do is get your 300 H&H loaded for.