National Magazine 30 Round Black Mag For Sig Arms P226/9MM - 9mm Caliber, 30 Rounds, Aftermarket Origin, P226 Model

I purchased two of these magazines and they are garbage. Neither one will cycle more then 1 round. The spring is way too weak. It won't push the next round up fast enough to feed. You end up with an empty chamber each time. When I disassembled them the follower(s) both had alot of melted plastic arround the edges from the factory grinding. And the spring is 1/3 the thickness of a factory sig and far less stiff. I spent over 100 rounds trying to iron out the defects and couldn't get more then 3 rounds at a time to feed. If you streach the spring out, it will bend back as soon as you load it. I knew for the price that they would be bad but I honestly did not believe products where made THIS BAD anymore. This is the only product I've ever asked for my money back.