Getting ready to try some P.P. in a G.M. barreled Remington roller in .40-70 ( 21/2" str.) Bore dia. (land-land) .400" groove dia. .408" I made up bore dia. & +.001" samples but since rifle is chambered for G.G., I had to full length resize case for snug fit on bullet. Since these are strectched .30-40 from Buffalo Arms, I was concerned about this much sizing each loading. I read about groove dia. patched bullets here..and here is what I did. My mould drops at .400, using BACO .0025" patching paper, dia. over dried patch is .408". Same slight neck sizing as with G.G. gave me nice snug bullet fit in neck. Of course bullets had to be seated deeper than ones patched to bore dia., but chambered rounds went in OK. I will only be using real black..Swiss 1 1/2 & Olde Ensford. That bullet is of course going to be real tight in bore..are there any concerns or pitfalls in my method? These are target loads so wiping after each shot is no problem. Thanks for any opinions.