I shot nothing but my 14 bore rifle for a year, almost every Sunday on the trail walk - 82gr. 2f GOEX and a .682" round ball, .030" patch. Come Rendezvous, I entered 5 muzzleloading trail walk events with it, placing 1st in every one of them. The 6th event was the BP ctg. match where I only placed in the middle of the pack. I was also happy with that event.
I only mentioned this year, as a note that calibre is not important - had I shot nothing buy my ,.32, or .40 or .45 that year, I am sure the results would have been the same, except for the ctg. event. there, the heavy ball and better range was in my favour as many shots were at 250 or 300 yards.
Pick a calibre in an accurate rifle, one you can shoot well and shoot that for a year, practicing every chance you get - at lest twice a month, then win every match you enter.
I have always done better with larger calibres, the mentioned 14 bore (.69), but also a pair of .58's, a SXS Kodiak and a .57 Musketoon, 1861, iirc, that did very well, before I sold them.
One lad at our club uses a .54, has for 30 years or more - HE is tough to beat. Another, usually uses his wife's .40, or his own .45 - HE also was VERY tough to beat, now, with failing eyesight, not so much - UNLESS he shoots his PH 1861 Musketoon, THEN he's still hard to beat.
Whether Taylor shoots his .40, or .50, he's tough to beat.
This sort of says, from .40, to .70 cal. take your pick.
Calibre is not really important, however,
