whilst i didn't purchase mine from here, because i live in UK, this blaster has been an absolute powerhouse. i used the AK blastermods brass breech kit, their metal plunger tube, and their 16KG long spring. this gives around 210 FPS, and isn't overly difficult to prime. the only issue i have had is that one of the thumbscrews that joins the priming bars and the boltsled has lost some of it's threading, so i have to rescrew it every mag or so. the strip down feauture is one of the best part too, as i can easily swap between my different internal kits depending on the arena. i have the stock internals with a K26 for casual play, the brass breech and metal plunger tube for outdoors, and used my 3d printer to make a short dart kit i use when in competive indoor use. love this blaster and recommend to anyone who is afraid to get into modding :)