Anyone here know any good ballistics resources on the internet for 12 gauge slugs or buckshot. I'm mainly interested in comparing the differences in the 2 3/4 inch shells vs the 3 inchers. My shoulder sure tells me there is a HUGE difference, but I have heard it said that there is not. I have been shooting mostly the Federal Classic rifled slugs in both sizes and the Winchester Super X's in 3". And I suppose this is another subject that's been beat to death here, but I missed it -- but is it preferrable to load 8 of the 2 3/4" in my Winchester 1300 Defender when in griz country, or 7 of the 3" shells? Slugs, 00, or a comination of both? I apologize if this is old hat -- just let me know and I will use the not often enough used "search" feature here...