I haven't had the opportunity to use this yet..thus,4 stars. It's heavier than I'd imagined it would be...Definitely feels solid. A single, handy tool for both .308 and .223 uppers. Being able to leave the charging handle and bcg in and still use this gives me confidence the receiver's not going to be damaged if I want to swap out a barrel. If the take down and pivot pins get munked up switching out a barrel which is the most stress torque your rifle should see using this tool..you'll know right away. i wouldn't blame the tool. There's certainly a better mouse trap out there..but for the money..for the individual 'do it yourselfer' that's gonna put this away and may or may not use it..it's money well spent.