A few days ago a friend I shoot with put some 28 gauge inserts into his o/u 12 gauge. These were the same length as the shells so they just fit the chamber of his 12 gauge. I was skeptical since they were so short. We shot a pattern or two and it looked amazingly good. Then he shot a round of skeet and it broke birds very well. And just about zero recoil. I picked up some of the plastic wads and saw that the wads were expanding to 12 bore diameter to make a seal. Really looked weird compared to the normal used wads. The shot column should have been very short. In that 12 gauge barrel, the smaller shot load should have been about like a pancake. I just wonder how well the wads do seal. In other words, do you lose velocity when you use a system like that? I have not seen any data showing if there is a difference.
