Depth of seating and chamber size is very interesting in how they interact with soft bullets and black powder.

I recall an article by Elmer Keith, written a very long time ago when he wrote for American Rifleman magazine, wherein he stated the bullet should always be sized or be of a size to fit the fired case with no sizing. At the time, he was shooting original Sharp's Buffalo rifles as there were no "replicas" at that time.

He noted there was NO sizing of the case to hold the bullet. The rifle he was writing about had been re-chambered (from .50 2 1/2") for the Winchester 3 1/4" .50 case. He noted that that case would hold 170gr. of 'rifle' powder.
When I read that article, years after it was written, I was playing with a Shiloh Sharps .50 3 1/4" and indeed, with the ICI (Scottish) single F black powder, the case did hold 170gr. and it kicked like a mule with the paper patched 700gr. bullets I experimented with from a re-bored mould.

The 'throat' in that rifle was a long freebore, not proper for a Sharps, but it allowed the groove diameter bullet to be seated almost entirely out of the case. It had to be wiped between shots to allow loading, thus was not useable loaded that way, for hunting.

With more commonly available GOEX black powder, 2F or 1F, the case held only 156gr. Thus, the specific gravities of those powders were quite different.