I shoot an old trapdoor and trapdoors were notorious for the wide variety of bore diameters. I have a more peculiar reload method than most folks. I have a plunger actuated spout that screws directly to the top of the powder can. The straight sided spout is just the righ diameter to fit the case mouth of a 45-70 case. I put the primed case on the spout tip the can up side down, push the plunger open and shake 4 times. Take the case off the spout and the powder is about 3/8 inch below the case mouth. I push the case mouth through an eighth inch grease cookie and then add a 457125 pure lead buller, lubed with cheese wax and sized in my 45-90 Ideal tong tool. The bullet and case are then loaded using the 45-90 tong tool to 45-90 OAL. I have never measured out the grains of powder, I never used a drop tube, I always use the same method to maintain consistency and always load up maybe a day before shooting, or even at the range. I believe shaking the powder can as the powder swettles into the case, is fairly equivalent to using a drop tube. Seating that long bullet over a grease cookie, also compresses the powder to the same amount everytime. The bullet is still out enough that the last grease groove is exposed, however, when loading in the trapdoor, closing the breech cams the long bullet nose into the rifling ahead of the chamber. So the bullet has no freebore to jump on ignition. My results have been excellent considering that my gun has some minor pitting annd a who knows how oversize the bore may be.
When last I attempted some BPCR silywets, I got 9 out of 10 rams at 500 meters. (Couldn't hit the chickens or turkeys to save my life. )