Radical Firearms is an awesome company with quality and crazy low prices. I have a few uppers from them and they perform well. The have a life time no receipt necessary warranty. I bought a used upper that wasn't cycling right they paid for the shipping to them fixed the gas port sizing and shipped it back to me only took 2 weeks. The only negative thing i have to say is that i dont personally like the coating they use. its not a typical black cerakote finish it is definently different. It's not bad but not as smooth as your typical rifle finish.