ranchand99,What
Triple Se7ensaid is correct,but believing that you are just getting started I will add a bit. Due to the lack of standards in the muzzleloading industry bore sizes even TC are somewhat flaky you will need to match sabot size to your individual barrel and their are a bunch. If you start by trying the sizes available to you from friends before buying it might save you some time and money. I personally would try the Mpp 12,the shock wave, the mpp 24 the standard harvestor and the crush rib.
In my Newest the 12 is to tight [hard to load] but will shoot ok the Shock wave is a little tight and will shoot one hole groups when I dont mess up. The 24 shoots almost as good and loads real easy and the crush rib is sloopy and wont hold a group. A little bigger [only a thousandth] could very well change what it needs to shoot good; I suggest try all keep records, its fun. Lee