Hard to come by are replacement SR-25 Gearboxes and if you are looking for one RetroArms have released their initial batch of CNC'd SR-25 Gearboxes... "CNC gearbox for airsoft guns SR25. Made of high strength aluminum alloy EN AW 7075th The first batch of gearboxes in a limited series of 20 pieces, orders were dispatched Wednesday, March 26, 2014. Other production will be in about two months. Fully milled gearbox version of the SR25 CNC machining center . Unlike other aluminum mechaboxům our made ​​from a solid piece of AW EN7075 T6. This is not cast as Chinese brands!

The gearbox is fitted with 8mm ball bearings, hardened steel connecting bolts and screws for mounting grips. The gearbox is significantly amplified along the entire length with added material. Of course, the use of standard parts for gearbox version SR25. Both halves of the gearbox to fit together with absolute precision bearings including holes that are 100% aligned.

(More photos at the RetroArms Facebook Page)

Other minor features:

• Large grooves for 2.5 mm 2 silicone cables
• Accurate hole to catch the reverse - the latch does not fall
• Accurate hole for the trigger - a lot do not jump even when using strong springs
• The guide grooves for the piston in one piece - no jamming of the piston on the rear window
• The groove under the triggering contacts - avoid possible short circuits when using MOS FET switches
• Micro-sized grooves on the pins that hold the trigger and spring shuttle feeder hangers - no popping springs
• Stopper shuttle trips - nothing to screw

Despite all the efforts we can not guarantee 100% compatibility Gearbox to all available weapons SR25 bodies. For most commercially available and can be extended brands gearbox installed without major modifications."