I currently have a couple of long barreled J P Sauer guns in 16 gauge, one 29 1/2" and the other 30". I am seriously considering chamber sleeving (yes, that's a correct terminolgy) probably one of these down to 20 gauge simply because I can't seem to find an older pre war 20 gauge gun with similar long barrels. The weight of both these guns is such that they would make excellent long barreled "overbored" 20 gauge bird guns, which is what I am after. I have a number of guns from which to choose an upland gun, and I have grown to much prefer pre war German guns for a number of reasons. Not many 20 gauge specimens around, it seems. If your goal is something similar to mine, or whatever your goal might be, chamber sleeving a 16 down to 20 is a perfectly feasible thing to do. If it should happen to be a fairly hefty gun, it might not make up into a particularly sweet swinging 20 gauge, but in my case, I believe both my guns will.
