I recently shipped a DPMS heavy fluted stainless steel AR15 barrel to GEMTECH to have them cut 1/2-28 threads and recut the crown. In case you're wondering the barrel has a 0.92" O.D. I didn't ask for a thread protector but they shipped the barrel back with a really nice one. I'll be attaching an AAC BLACKOUT 51T flash hider shortly but the thread protector sure is a nice touch. Anyway, I thought I'd give credit where it's due and GEMTECH did an awesome job for anyone thinking about having a barrel threaded. They make great suppressors too!!