muzzleloader questions

[Cossack]

I'd go with 50 (again) more supplies are available. In line or not can depend on where you play to hunt. Some states do not allow in line, 'primitive' only for their ML season and special hunts.
If that isn't an issue, I'd go with a fast twist (29) to take advantage of the accuracy and ballistics of sabot loads.
I'm shooting the Encore because I like other versatility it offers (can convert to rifle, shotgun even handgun). It's its a dedicated ML there are other less expensive options available.