So, I've got the itch to shoot buckshot in my 20 gauge 870 and factory 20 gauge buck just doesn't exist here. 20 gauge target loads are cheap and plentiful though. Would it be feasible to uncrimp the birdshot loads and fill 'em up with #4 buck instead? Of course, I wouldn't exceed the original birdshot weight. I have an old 20 gauge Lee Loader tool that I could probably use to recrimp. I know it's not going to duplicate premium buffered loads or anything, but would it at least be good enough for the typical range of, say, magnum #4 shot? Or, how about replace the birdshot with lead BB or other shot?