Pro line brings up a good point about the 410 slug, if you're gonna go single shot may aswell go with a muzzle loader that way you can tune the gun to about any load, for my 50 cal ML I have a light load for my wife shes extremely recoil shy the load is plenty potent to take a deer to 75 yards maybe even 100. The load is two 30 grain pyrodex pellets under a bullet/sabot combo i put together its a .451" dia. hornady sabot with a winchester 45 cal. 230 grain notched jacketed hollow point the bullet is actually a 45 acp slug, its designed to expand at pistol velocity so im not worried about expansion problems the load is rather accurate out of my CVA hunter bolt approx. 1 inch groups at 50 yards and 2 inch groups at 100 yards. the recoil is between a 410 3" game load and a 30-30. just food for thought