Your Mileage May Vary
I can’t give you the perfect load since each rifle has its preferences. With the powders I used, their position in those huge cases proved to make very little difference with the WLR primers, so don’t sweat it. Just do not use fillers or substitute slower burning powders.
The small flats on the noses of the modern MP and NOE collar buttons are intended to make them safe to use in the magazine tubes of lever actions. The pointed nose shape of the Lyman, NEI and Rapine bullet designs pretty much make them a two-shot proposition for lever guns.
There are two easy ways to keep the magazine tube spring from shoving the bullets deeper into the case. One is to simply roll crimp the case mouth into the lube groove just under the top driving band, if your rifle has sufficient freebore ahead of the chamber to allow it. The original specs for the .45-70 called for zero leade in the barrel, with the rifling beginning at the very end of the chamber, so this may not work for you. The original collar button bullet was intended to be seated with the top of the front driving band flush with the case mouth.