I haven't had to send my MP15-22 back to S&W, but after about 400 rounds I began experiencing frequent stove pipes, then once found my extractor sticking out from the bolt at 90 degrees. It fell out into my hand when I touched it, but all the parts were still there, i.e., the spring and the little flat bar behind the extractor. I reinstalled the extractor and continued to have one to five stove pipes per magazine with seven different magazines. I tweaked the ejector bar with a screwdriver and now have shot several hundred more rounds without a single stove pipe. I have second MP15-22 that has been flawless. So overall I am quite satisfied with the MP15-22. As for being accurate, I have no complaints with them.