Benjamin Best Slugs for Lothar Walther Benjamin Marauder .22 (non choked)

I’m sorry if this has been asked before, but I recently picked up a Benjamin Marauder .22 with a non-choked Lothar Walther slug barrel and I’m looking for advice on ammo. What are some of the best slug choices for fox/coyote hunting that won’t break the bank? Also, would you recommend .22 slugs or .217? I’ve heard good things about both and I’m not sure which diameter tends to shoot better in this setup.
 
I’m sorry if this has been asked before, but I recently picked up a Benjamin Marauder .22 with a non-choked Lothar Walther slug barrel and I’m looking for advice on ammo. What are some of the best slug choices for fox/coyote hunting that won’t break the bank? Also, would you recommend .22 slugs or .217? I’ve heard good things about both and I’m not sure which diameter tends to shoot better in this setup.
For coyotes and fox I would look into the Olympia shot slugs, I've seen good thing about them and they are a solid slug.