There's nothing wrong with your Henry.
It's very easy to find out what part of the bullet is too fat to chamber.
When you ramrod the stuck boolit out of the bore you will see abrasion marks revealing the problem area.
If it has a (approx) .300 diameter bore ride portion north of the (approx) .309 full diameter driving band diameter, there might be a sign of interference there. Otherwise, the leading edge of the full diameter bearing surface will be scraped.
In the latter case, just seat the boolit deeper. A fat bore rider is not so easy to solve.
A tight throat like yours is much more accurate with cast than a sloppy one. Just need to adjust the boolit fit.