Help required with powder primer choice for loading shotgun cartridges. I’ve loaded rifle ammo for a long while but centre fire seems more common, it’s a different animal to shotgun reloading. Looks like plenty of choice re powders, so which one do I choose? Are they all really that available? Which primers for reloading old factory carcasses? I’m starting with #7 lead shot 28 gr on clays initially. Many thanks