Finally got my MAC-11 steel kit working reliably. Wii-tech aluminum nozzle to the rescue : r/GasBlowBack
Hop up adjustment wheel for marui wii tech gas pistols (wt-4523): Hop up for Softair | Titano Store
Masada (A&K) Hop-up chamber, spring, switch, hop up bucking and rivet - Wii Tech
Wii Tech - High End Airsoft Parts, Accessories & Replicas
Hand guard rail with short slides for m870 wii tech (wii-04033): Ris - ras - handguards for Softair | Titano Store
WII TECH - CNC Aluminium Enhanced Hop-up Compression Bar for Tokyo Marui M4 GBBR Series
Wii Tech Rubber Stock Pad for KWA / KSC / UMAREX MP7 Series GBB SMG's, Accessories & Parts, Gas Gun Parts, Rifle Receiver Parts - Evike.com Airsoft Superstore