I use a set of homemade chambermates to shoot low pressure 12 ga. shells in one of my 10's. Any machine shop can make them if you do not have a metal lathe or buy them off the shelf these days. If you get 6K psi in a 12 ga. bore it will only be less in the larger 10 bore. Some of the real low pressure loads do not burn well for me in cold weather and I no longer load them anymore. There are several excellent, low pressure 12 loads, that are a snap to load. And the supply of 12 ga. empties is a thousand times better than the supply of 10 ga. hulls.
