The huge grease grooves will help with fouling when using real black powder. I suspect with smokeless, LBT Blue is largely wasted - money and volume. Perhaps with smokeless you might consider lubing the bottom groove only.

Considering the low velocity you'll be driving them, I'd merely mix up some beeswax and Vaseline - about 60BW:40Vas -much cheaper and an excellent lube in large bores to over 2,000fps.

I'm realy quite excited about Dave's bullet - has the basic shape of a TC .54 Maxiball, with much shallower grooves and wider nose- both immense improvements. The Maxi's deeper grooves in all calibres, promotes bullet collaps instead of expansion, whre the bullet's nose folds back into the huge grease grooves, rather than mushrooming out. this won't happen due to the heavier shank in Dave's bullet. Shallow grooves would work as well or better with straight smokeless, but large capacity grooves work best with BP's fouling, expecially in hot weather.

When using black powder in shotshells in range testing, the hulls go into the trash barrel after shooting - I do not clena them. When hunting with them, they stay where they land. Around here, once fired trap shells are free for the taking - Fed, RP, AA and all the obscure hulls on the trap range that continually fill garbage barrels - thousands upon thousands. I suspect this is the normal situation at most trap ranges, considering loading trap shells costs about the same as commercial.