Ultimate m4 DMR

Hey guys gorem back here again with a new project. Recently I've been running as a basic assault class, but now I have a chance to build another DMR. I've built many in the past and now I'm combining all my past building knowledge into one build. The gun will be a combination of a classic army metal body and a G&G gearbox. The gearbox already has metal bushings, metal tooth piston, and a systema spring guide. I'm putting in a prome. 450 mm barrel and i'm going to be using a extended silencer on the front to cover up the barrel as well as damper the sounds. I'm building the rifle for operation lightning strike which will be here in Michigan during the summer. Because it's a lion claw event, I'm required to keep the fps under 430 so I'm going to have to pull out all the stops to buil the best DMR possible.

To do:
1. Balance the cylinder
2. Seal the hop up
3. Silence the piston

I'm going to be posting posting photos this Monday and as soon as it's up and running I will be posting videos.

I'm running into one problem, I have a motor that has a stripped pinion gear, but I don't know how to remove it without the special tool. If anyone has ideas just let me know.