SMG is best miner's weapon and key to profit, works against NPCs and miners with mats in inventory. Too bad you need a friend for 2nd action, as guard don't like it, still it's better than waiting and spaming rocks with hammer. Also miners always have only 2 minerals/ore because they simply can't have more, as it replenishes one by one, and you can't get more than 1 swing from one sources, so you'll spend 10 bullets on 2 minerals/ore, what isn't good actually.