I was forced to use slugs for deer growing up in Ontario. In those days we had Fosters from fed, Rem and Win. They were terrible. Then I found Brenneke Rottweilers and put a scope on my 870 and everything improved. Fast forward to now and my bear outfitter uses the 870 with a short imp cyl barrel and Brenneke slugs for follow up work. Having seen first hand the damage they can inflict on a large bear, I would have zero hesitation using them for backup work.