About the middle of July I bought a new S&W factory 12 rd mag for my 6906 from CDNN. It came sealed in it's plastic box and I just looked at it and put it in a drawer. Brain dead.
Last night I got it out and started to stick in the gun. Would not go in without a strong push, would not eject without pulling it. Also the slide release lever on the side would not move to release a retracted slide.
When I looked at the mag the lips were much to close together and the cartridge follower or platform was binding and not raising to proper height.
The sad part is, when looking at the CDNN page, it says no replacements after 3 days. After that you have to send it to the manufacturer.
I am going to call them tomorrow and check but I doubt if I have much chance after this long. When you purchase an item, even factory new, do not wait before you check it out.