Save your Merkel from the abuse of these type slug loads. Get yourself a Benelli semiauto or pump which handles all lengths of 12ga shells and all types of shot/slugs. I just made a similar choice for a predator gun to use on coyotes, bobcat, cougar etc here in AZ. If you get a second hand Benelli Nova Pump (I paid $229) it will cost less than the chamber and barrel work and you won't be concerned about beating up the gun in the woods as it is already uglier than sin. Right tools for the job!