You did run out of lube, and dang near ran out of bullet metal! But it still actually worked pretty well all things considered. Easy to tweak from there.
Back to alloy again. What does Brad need? Obviously tougher, and like Fiver wrote water-hardening isn't going to do enough with that particular low-antimony alloy. I like to use low-antimony alloy, heat treated, (like 2.5/1.5 alloy HT'd to 19-20 bhn, made from 3/2 clippy weights/soft scrap and 1% tin thrown in on top) because it doesn't lose so much metal to drive side abrasion as something like straight wheel weights does. BUT, when you need a tougher alloy to handle the rifling at high speed/steep angles, that means more antimony automatically......but how much or how little tin to go with that to keep the abrasion losses down? 4/3? 5/2.5? 6/4? #2? I think that question is absolutely key to all this HV work.