02 November 2018
All the arithmetic in the world doesn't make a cast bullet behave like a jacketed bullet. Cast bullets are not sensitive to twist/bullet weight/velocity like jacketed bullets. They are, however very sensitive to fit. First see if the bullet chambers un-sized. If it doesn't, use the minimal sizing that will allow chambering. A slide fit to the chamber is easily verified with an inked bullet dummy round. If at least the first driving band shows a slide fit and you can feel the bullet takes 1 to 2 pounds more push to chamber than a jacketed bullet, Congratulations you have an excellent bullet size that fits your rifle with a stable fit to the chamber and THAT is where accuracy comes from with cast bullets, NOT ARITHMETIC.
A good fit with either bullet at 22 RF velocity and you should expect 1" groups or less at 50 yards. You don't need any special lube, Lee LLA or Whites Deluxe 45:45:10 don't have velocity limits when bullets fit first. I tumble lube once lightly with warmed bullets and warmed tumble lube once before sizing and once after. If you are not sizing then one coat is fine.
You could be a daring kind of guy too. IF you get the fit I described and your bullets are pure lead for that load level, you won't even need lube. However, if your fit stinks, you will have barrel leading up the wazoo.
It is important to note that you should only chamber and fire cast rounds that fit like this once. If you extract a round like this, the fit is gone and it needs a new bullet. Don't fool yourself with fit. Re- chambering rounds that fit like this causes them to shoot all over the place.