I've run Missouri, SNS, Brazos and Summers HyTek Bullets over 1500fps in revolvers and lever actions with no leading at all. I did try some Bayou a year or so back and started getting some leading running just over 1000fps. I think I just go a bad batch of bullets as I could scrape the coating off with the edge of a knife. I took the rest of that batch and loaded them really light and had no problems. The main reason I use HyTek is I can load them as hot as jacketed and barrel is just as clean, so I'm betting the OP has either got a bad batch which could happen or the coating is getting scratched during loading.