Is it conicals (as in maxi bullets) or sabots? If it's sabots, I've used Powerbelts and they absolutely DESTROY whitetails. I've also shot whitetails with round balls out of a flintlock and the biggest thing with them is they're only accurate out to MAYBE 100 yards, 50-75 is more like it.
The round balls hit like a truck though. Given a choice, I'd go with the sabots if legal.
Is it flintlock / percussion (ie, traditional) only or can they use "modern" muzzleloaders (ie, inline)?
"Knowing when to shoot and when to wait is one sign of maturity in a bowhunter. Be patient and pick your aim point carefully." ~ Randy Ulmer
"I suppose it's the way of hunters. We are very odd fellows." ~ Peter Hathaway Capstick