"… all need cartridges/shells" but I haven't a clue. Well, I have a few clues, but no powder, few primers, some lead weights, and no knowledge.
Right now, my two biggest concerns are getting powder and fixing my well-used MEC 650/12 ga press. There's no BANG! without powder, and without a BANG, nothing useful happens at the other end of the barrel.
The MEC needs a lot of TLC and a few parts. Mayville Engineering Company has tried to be helpful, but to get good answers, you gotta ask good questions, and I'm not knowledgeable enough to pose the right ones.
We own six weapons: two S&W M&P 9mm pistols, two Sig Saur .22 Mosquito pistols (to practice with, but "any gun will do if YOU will"), a Remington 700 .308 Win rifle, and a Remington 870 12 gauge shotgun. I'm up for a few more (especially a home defense shotgun), but my Jacquie is alarmed at how much this has cost — $2,500 in gunnery, $2,500 for the reloading presses (one doesn't even work), and $2,000 in ammo and cleaning supplies is overwhelming her. If I don't start producing cartridges soon, I may be in the doghouse (and we don't even have a dog — no doghouse, either).
We also have a Dillon 650XL press for the cartridges and the equipment and supplies to make those wheel weights into boolits, slugs, and shot. (That's another issue, but just as important to us.)
In any case, starting out in the wonderful world of handloading is only one part of being ready. Jacquie and I are hard core suburban "preppers". We feel compelled to get ready for everything from Amœbæ that eat your brain to EMP and on to a Zombie apocalypse (maybe not actual zombies, but we want to cover from "A" to "Z"). We have the equipment to install solar panels (with battery backup) and much more. Our back yard is "food production unit": I'm wholly uninterested in watering anything here in semi-arid Colorado* that won't feed me (but she has a few rose bushes and 101 flowering bulbs). Once I get it running, our aquaponics system should provide 80% of our non-grain, non-dairy food. It'll never pay for itself unless Kroger can't restock its shelves; but then we'd be the richest people on the street. (Which is why we're so interested in self defense.)
* The recent floods notwithstanding, we usually have water restrictions from April through November.
Two decades ago, I retired from the US Army after 21+ years. I served as an enlisted Infantryman and a commissioned Signal Corpsman. Now, my goal in life is to help people eliminate all debt from their financial lives. We have seven children who've given us 30 grandchildren (all of them educated at home, often at OUR home). All seven families want me to do the experimenting so they can all reload their own cartridges/shells, too.
Since I'm 65, with five eye operations under my, er, belt, and have recently had a heart attack (another reason to be prepared), I'm not likely to do much hunting. But there are deer in the "greenspace" behind our house. In a really cold winter, or when there is no fresh meat at the Kroger/Safeway down the street … , well, you get my drift.
From what I've been seeing here, many of you experienced handloaders know my situation, having been there yourselves. My hope is that, one day not-to-far off, I'll be one of those answering questions, but for now, I'll mostly be asking them.
All the best,
Le Sellers