I have an Army Navy CSL 28 ga hammer gun with BP proofs. It is a 2 1/2" gun with 28" brls. I have not loaded any black powder and after looking at various sites was wondering if the brass hulls or 2 1/2" plastic would be the way to go. Has anyone used the metallic cartride? I roll crimp most of my field loads with the plastic hulls but how to you maintain your crimp on the metallic hulls. Also what black powder would be the best to use in the small bore 3/4 oz load. Thanks for any info. Dwight