I tried a purpose designed slug for the Kodiak 12 bore and it failed miserably. I am strictly a RB shooter in the doubles and big bores now. As far as the patches, it is the material that is failing, as one type holds up and another gives out. Also a lube mixture of Olive oil and Murphys Oil Soap whipped in a 50/50 seems to have solved a lot of the problems. I also use a 12ga shotgun wad base (cut off the wad) over the powder, then the patched ball and my lube mixture. This has allowed me to shoot up to 200grns BP without cutting (much). I've lapped the barrels as well and this helped some. Triple 7 shoots the best, then BP.

Colorado