I have a couple of ProMags, 6 rounders. I use them for range shooting. I've had no problems with them but some people seem to have a lot of issues with the 10 round mags. I had one of their MKII mags and it was crap. I'd say their quality is hit or miss but for just range shooting I don't have a problem with the 2 I have and they were about half the price of a factory mag. I have a couple of them too