Guarder Aluminum Slide for MARUI HI-CAPA 5.1 (STI / Dual Ver) Type74 G&P have answered both these

G&P have answered both these points with their Gas Charging Collapsible Stock Set which also comes with a very ergonomic pistol grip set so you can alter the size of the grips for your comfort

Acetal and Steel Package Includes SP120 Spring (Oil Quenched/Tempered Si-Cr Alloy Steel Wire) Polycarbonate Piston Air Seal Nozzle Ball Bearings Spring Guide Polycarbonate Ventilation Piston Head Stainless Cylinder Head Lucid Chromium Plating Cylinder Original Type Steel Gear Enhanced Tappet Plate 6mm Steel Bushing Shim Set SUPER-LUBE Oil X3 Manufacturer Guarder Hop-up N/A Shooting Mode N/A Gearbox Type 3 Fit Battery Pack N/A Bullet Type N/A Pistol Power Source N/A

When it comes to 1-1 replicas

Product Code     F-1911H

Magazine Capacity: 21+1 rds (Std)

Guarder Aluminum Slide for MARUI HI-CAPA 5.1 (STI / Dual Ver) Type74 G&P have answered both theseFULL ALUMINUM DIECAST CONSTRUCTION Design for Gas Blow Back Pistol Tokyo Marui HI CAPA 5. 1 & Custom Dual Stainless Series Replace original ABS Slide Best in conjunction use with high flow blow off valve Please note self installation is required