45/70 different length.

[Freightman]

I have two 45/70 BPCR and I was measuring the chamber to make some dummy rounds to know the seating depth. One is a Shiloh Sharps Big Timber rifle and a 500gr boolit seated to the crimp grove and measures 2.752 just engraves the lands which is a- ok as if it fits it shoots, the boolit is .459 by the way.
Then I have a Norway rolling block that shoots the 45/70 with no bulges but the chamber is 3.046" with the 500gr .459 boolit which engraves the lands barely, so here is the question do I load it out that far? or do I load it back to the crimp grove? Here is a picture of the difference.Here is a target shot with the Rolling Block shot at 50yds and there were 30 rounds with 60g ffg and a veggie wad. (wiped after three rds and patch ran through every 10 rds.

[zuke]

Do what work's best in you rifle's.

[Lead pot]

It doesn't surprise me that the Military seats out farther even tho that chamber used a shorter case then the .45-70. The Norwegian rollers were a 11.4mm, smaller then the .45-70 Shiloh's .458 that is a 11.64mm.
The roller has a longer shallow lead and old military throat is usually on the large side in the old black powder cartridges.
As long as you load it with black powder there should be no problem because the bullet will upset good enough to seal the bore.
It should make a fine shooter.