I'm putting together a list of what I'll need to build a second gearbox for my m249. I want this gearbox to be a high speed setup, so I'm planning to do a dsg setup. I just need opinions on the items I'm buying and if they are worth getting or if I need to find a higher quality part in its place. Here is my build list. What I already have. M249 gearbox Siegetek dsg Shs tapped plate 18:1 gears (xyt or Shs, I have both) Burst wizard 3 (newest model with micro switch protection, hardwired not plug n play) Metal spring guide (polished) What I plan to buy. Shs brand- 14.5t piston Shim set Bore up kit v2 Lonex brand- Pom lmg air nozzle A2 short torque motor Everything else- Modify 8mm tempered steel bushings Sorbo 3/16 70d bore up Neo pad 1/32 70d 20a micro switch M160 spring (zci maybe? Not sure if that brand spring is any good but heard good things) My goal is 45-50 rps @ 300 fps. I may buy a new set of 13:1 gears later if I'm not happy at that speed but for now I just want to use the parts I have to get it up and running and go from there. My M249 is a Para model with 363 inner barrel so I chose the bore up parts to help insure I'm not getting under volumed after I short stroke the piston. I know most of you are going to say not to use the burst wizard, but I'm not flexible here, I've only had good experiences with them and unlike what is said about them they do offer trigger protection if they are hardwired. Especially the newest model which has micro switch protection, which is exactly what I need. Before I'm asked, I'm experienced working on gearboxes and know about high speed setups. I'm building this gearbox separately from the original so I can swap them out to suit my needs for different games. My box mag is upgraded and wired to my trigger so it should have any issues keeping up with the feeding.