hi,i would like to use one of my existing guns to create a dmr(my gun tech will actually be doing the job).we are going to use a heavily upgraded g and g combat machine as the base gun,he is very confident he can make a great dmr out of this platform, would change hop chamber,hop rubber,spring change,maybe new nozzle and piston head too.locked to semi also.i was just wondering if anybody has made a dmr out of a similar platform to the combat machine and what the performance was like