I have shot Muzzle Loader Rifles since I was a kid, but I never owned one before and I never hunted with one before, since I never had tags for hunting muzzle loader before the past couple of years.
My experience is limited to what I have done with TC Hawken 50 / 54 Caliber rifles.
Truthfully I have yet to harvest a deer with either rifle, I own one of each.
I have both round balls and conicals for each rifle and the only thing I can say is that I don't use a patch with a conical bullet. The bullets I have were sealed in a foam package with bees wax and they go down the barrel - once you get them started, very easily.
I have shot the rifle at 25, 50 and 100 yards and I can attest that the conicals seems to be more accurate and they expand upon impact and I am very impressed with them.
Unfortunately the rifles I bought are not prime examples of neither accuracy or are in pristine condition. I will need to spend some time removing the lead fouling from the rifling of the barrel of the 54 caliber Hawken - after the season is over.
Truthfully, the barrel was full of rust and I spent weeks with a brass brush, Hoppe's #9 and patches, swabbing out the barrel. Soaking the barrels with PB Blaster.
Just as the seller claimed, after a couple of shots, the rust disappeared.
I actually enjoy shooting the 54 and clean up is a breeze with just some Dawn Dish Detergent, Hoppe's #9 and some elbow grease - while shooting the Conicals.
I normally use 90 - 100 gr of 2F black powder.
My neighbors told me to fire / unload it every night!
I've never had a misfire or a problem, following the rules forum members and internet advice that was given to me.
Now round balls just seems like a pain, having to use a patch, having fouling in the barrel from the patch lube. I might even use my Hawken Muzzleloader next year in deer rifle season, it's that enjoyable to carry and hunt with..
The only downside I can see is only having just one shot, having to fire it to unload it every time you hunt with it. Having to clean it as soon as you get home, after hunting - every day!