RE: Question about APP
Are you talking about the Black Diamond made by Thompson Center for the rifle you are worried about the barrel? If there are ruff sports in the bore (which I doubt) the shooting of the maxiball will knock that out of the barrel. Whether the barrel is smooth or not, it is very possible to get some lead build up in the barrel of your rifle. That is why you clean the bore with a brush and a solvent that removed lead.
As for the American Pioneer Powder their mention for not using lubes I believe applies more to people that bore butter the barrels or leave the oil in the barrel and then load. APP is known to react with that oil and make a sludge. I've shot APP and Pinnacle with conicals that were lubed and never experienced any problems. I will say that shooting conicals, was not attheir best with the APP or Pinnacle. These powders in my rifles seemed to like the smaller lighter conicals up to 300 grains. Your results will be interesting.
Use some solvent on a patch and swab the bore of your rifle clean. Then run a couple dry patches down the bore to make sure the barrel is dry. APP is said to be very moisture sensitive. I personally have not found that to be true, but some of the people who posted the facts, I learned a long time ago, not to doubt their word.
I would not remove the lube from the maxiball. The lube helps protect the lead conical from the heat of the powder ignition, and it assists the conical in expanding to capture the riflining in the bore spinning in a uniform manner and getting the most accuracy out of the projectile.
If the lube worries you, try putting a unlubed felt wad under the conical. Granted it will be distroyed by the ignition but we do not care about that. All the unlubed wad might do is absorb any lube trying to work its way to the powder charge. To make unlubed wads, get a 1/2 inch hollow hole punch and some construction felt and stamp out a bunch of them.