The .45 has been a favorite caliber of mine for years...that said, I do feel a little undergunned with it compared to the larger calibers...shot placement is always importanmt, but with my .45 I am the most sensitive about shot placement, no bones, etc...I consider it the .243 of muzzleloaders.
Hunting in fairly thick woods the longest .45cal shot I've taken was a 6 pointer at 60yds...waited for a perfect unobstructed broadside line through his heart and he dropped in sight of me.
But, unlike all my other caliber PRB loads which make complete pass-thoughs, the little .440" broke a rib going in and stopped on the far side bulging the hide behind his far elbow...(90grns Goex 3F, Oxyoke wad, .018" P/T).
When I think of extending that range from 60 to 100yds I know there will be a lot less steam behind that little small mass 128grn ball...and that's what makes me feel a little under gunned..."marginally-gunned" might be a better way to say it...at longer distances.
I do think the .45cal is an outstanding caliber for general woods hunting for the typical 25/50 to 75yd shot but if I was going hunting in an area where the "average shot" would be 100yds (75-125yds) personally I'd take a larger caliber...that's just me