I live in a slug zone, and have hunted with slugs, muzzle loaders amd high power rifles. And have seen success and failure or near failure with them all, so here are my thoughts: slugs CAN be effective, but you need a dedicated barrel or gun, amd there are a few thongs that can get you in trouble with slugs, they can show extreme dislikes of certain ammo, not from a 3”group to a 5” group. I am talking “WTF?! How is it not on paper?” A fouled barrel can do almost the same thing in very very few rounds, sometimes they throw fliers for no apparent reason, i am still not sure if it is ammo quality or barrels getting dirty, but i think some of the deer that are lost that people swear they had good shots on are fromfliers from fouling or crap ammo. I have spent more time amd money loading my own slugs and buying 100 different loads only to find that i cant find the same lot that shot good last trip to the range amd the new lot is different (usually worse) I almost always go for my muzzle loader in the shotgun zone close to home.
Not trying to be a negative eehhhh hole but i will be blunt, I think using a slug gun where you can use a rifle would be pointless.
I commend you for looking for something more effective but look elsewhere, bullets, loads, rests shot placement ect. Also, i have a long near failure story of a deer shot right through both lungs in the right spot with a 270 with the wrong bullet that went a long long way. The bullet was to hard and didnt kill fast enough even with a good shot.