I have learned that guns and gun parts are like tools and, in general, you get what you pay for. Anytime you don't buy an OEM part you run the risk of needing to do more fitting than if you do, but the better the quality of the after market the less time you will spend. I purchased a mainspring housing with magwell based on price, and as I polished the mating surfaces to make it fit I ran into voids in the casting. I then purchased an Ed Brown for nearly twice the price, it looked finished coming out of the packet, and it slid right in. Every once in a while I need to be reminded that it is worth it to look at more than just $$$.