I purchased a 15-22 about a month ago. The serial number begins with "DV". I assume the writer of one of these replies was refering to a serial number "a model DT or newer DU", so I guess mine is even newer. I have fired approx 1000 rounds in the last month with one FTE (rifle was brand new at this point). The ammo I have used has been varied - Bitteroot Valley Ammunition, Federal bulk, CCI, Fiocchi. No problems. You didn't mention what problem you are experiencing, but I guess it is FTE, as those problems are mentioned most in what I have read. If so, YouTube has an interesting video about correcting this problem. Seems simple and makes sense. HOWEVER, all reports indicate that Smith and Wesson has been very aggressive in correcting problems with 15-22's, so I would consider that option first. All in all the firearm is one of the most enjoyable, affordable (and fun) .22LR's on the market. Very accurate for what is it, but impressive. I was accually doing better at the range with the stock (metal) sights that came on it than I have been with a new Bushnell Red Dot I got especially for it. It's a great little rifle.