The gun that you have: VFC HK416A5 Your Budget: I'm honestly going at this with an open wallet, but perhaps no more than $400? Your Goals: Rate of fire: Aiming for around 22~24 rps. Gun currently fires around 19 rps on full auto. Velocity (FPS): Operation between <330 FPS w/ 0.2's (~1.0j, achieved with a cut M95 spring) and 405-ish FPS w/ 0.2's (1.51j; stock spring, used for outdoor) Range: 50-125 ft Accuracy: I'd like to be able to hit center mass of a man-sized target at around 100 ft reliably and consistently. Your previous teching experience: Limited to disassembling TM-design M9s and opening the ARES UMP45 V2 AEG and replacing the packing and barrel. Willingness to learn to DIY and tech: Willing to learn how to maintain it, but I'd rather it be built professionally as I don't trust myself with what I want on this one. Your gameplan so far: These are the parts I've considered so far. * Gate Titan * Tienly 30k (from Guges) * SHS gears, but still not sure on what ratio to get. I believe the stock ones on the gun are 22.23:1 if my math for counting gears is not off. YouTube says 16.9:1. * Replacing barrel to a Lambda 6.01 with rhop Any outstanding conditions: I live in the USA so sourcing parts from overseas retailers is not ideal but can be done if need be. What Role/Type of Play You Will Be Doing/Playing: CQB and Assault, so lots of semi and not a lot of full auto. [insert generic "T R I G G E R R E S P O N S E" here] Other airsoft stuff you use in/on your gun: Battery: Currently a Turnigy 3S 1000 mAh 20~40C lipo, but will be switching to the battery packs Guges stocks once they arrive. BBs: Stuck to 0.2's for CQB. Outdoors, 0.28's or 0.32s (or whatever is recommended at my max range. 0.28's have just been what I had been using). Actual question(?): I'm looking into modifying my HK416A5. Planning on getting her built up to be more for outdoor use, but with the flexibility of being used indoors if need be in case a friend of mine wants to join in on the CQB fun (have the UMP45 as my primary for that). With this in mind, I've decided to go for a low-ish (22~ rps, is this still considered low?) stress build so I can swap springs and not have something blow up on me. With my limited tech experience, I'd like to minimize having to open her up to replace something. Another thing I'm looking into improving is the reliability of the internals. VFC isn't quite known for having amazing internals and some of the stock parts can be dodgy, i.e. the gears, piston, and tappet plate if I recall correctly. The shimming, AoE, and whatnot will be done by a tech. I do intend to replace the built-in mosfet with a Titan and get rid of the in-line one she has going right now. I'm looking for input on parts to grab/not grab so I can reach my goals above. If I'm misinformed about anything, please feel free to point me in the right direction! Thank you in advance.