I've had my Buckmark for ten years or more, and love it. But anytime I get a misfire, the culprit is the same. I get out the allen wrench, tighten down the rear sight a little, and everything is back to good again. It usually takes about 200 rounds for it to loosen up, but not always.
As for being finicky, mine will NOT shoot W-W's "Xpert" 22 ammo, ever. It refuses to feed in several other guns, both rifle and pistol. Nothing else has caused any problems. I used to shoot a lot of Rem bulk ammo, and got a higher rate of misfires than with any other ammo, so now I just buy the cheap Federal stuff, and have no problems. HTH.
PJ