My brother has a Remington 870 with a rifled shotgun barrel he can put on for deer hunting. It is a magnum so it will accept 3" shells. The place he bought it from told him he had to use 3" sabot slugs with his slug barrel. I told him I did not know why he couldn't use 2&3/4 inch slugs if he so desired, and that I didn't understand what the barrel had to do with his reciever that accepts 2& 3/4 inch and 3 inch shells. So they will sell him 2 &3/4 inch shells for bird/rabbit hunting but only 3" magnum sabots for deer hunting. I think they just want him to spend the extra money for the 3" shells. Am I crazy?? 2 & 3/4 should be fine, right? Thanks.