i own one for 2 days now, all i can say it's he's not build for performance, well made but need some job to be powerfull enough, the TP is 3mm larger, i already disassembled it and i'm going to help him to breath correctly with a tp of 4.5mm, the barrel breech need to be modified, the transfer port isn't aligned with the tp of the block and the airflow isn 't optimal.