Try this as a rule of thumb.

Patched balls and plastic sabots will wear a barrel out with 3.2 bazillion shots.
Conicals will wear one out in 2.9 bazillion shots.

So yes, the conicals will wear it out faster.

Muzzle loader barrels die from improper cleaning, short started loads, or muzzle wear from loading. Muzzle wear is easily fixed with a crowning job or, in extreme cases, cutting 1/2" off of the barrel and recrowning.