The single shot adapter is basically just a solid, blank magazine that allows you to shoot single shot easier. I stole my sons from his youth scout and got him a 5-shot.
I put the yo dave trigger kit, aluminum mag well, the extended release, and the bottom metal in my American. That trigger kit is the chit for very cheap, I can't imagine needing anything more. My plastic mag well never broke but the magazine never really felt like it snapped in. I always ended up checking and double checking that the mag was in all the way. Now with the aluminum well and extended release the mag snaps in very nicely. There is no doubt now when it locks in. The factory bottom metal seems a little cheap looking though it works just fine. The DIP bottom finishes it off nicely.
The switch barrel feature actually works very well. I just keep an index card with the scope adjustments for each caliber; 22LR, 22mag, 17 HMR. POI has never been an issue for me.
