I've have no complaints about the one we own,as it was bought new. As for ammunition, this one seems to like the Federal plated ammunition. It's been known to take a deer sort of out of season,but that was a long time ago, statute of limitation done expired.lol. As far as the best ammunition goes, every gun we have has preferences,as I'm sure you know.
According to what we've read the micro groove barrel was bored out to the size, then the rifling was cut in individually, unlike most of todays, where the rifling is usually cut all at once. Seems to me doing it one at a time would keep the barrel cooler and thus allow for a better accuracy rate, but that is just my opinion.
Never had this one jam up on us or any other problems that come to mind. It is always cleaned and oiled after every time we shoot it and when in storage is oiled about every 2-3 months for safety sake.Keeps the rust away and can keep an eye on the condition of it. Hope you get yours fixed, as they are fun to shoot. Hope my opinion helps,