This set from Western Arms covers pretty much all of the internals that go inside a WA GBBR M4 receiver. Absolutely everything, including a negative pressure bolt carrier, buffer tube and buffer; in fact, all you need is a receiver to install this stuff into and then add a front set, barrel, grip and stock and you have a complete GBBR.
A prime example for putting this too use, purchase a Magpul receiver, grip, stock and front set then select a hop-up, inner and outer barrel of your choice and you have a complete custom GBBR M4 with no wasted parts.
- WA 6 Position Stock Tube
- WA M4 Aluminum Buffer (WP81A)
- WA Recoil Spring
- WA Complete Bolt Carrier (Negative Pressure)
- WA SPR Type Cocking Handle
- WA Selector/Pin/Spring
- WA Bolt Stop/Spring/Pin/Firing Block/Pin/Firing Pin/Spring
- WA Forward Assist/Spring/Pins
- WA Trigger/Spring/Pins/Sear
- WA Magazine Catch/Spring/Trigger Guard
- WA Hammer, 120% Spring, Pin Set
- WA Hammer Lock Set
- WA Buffer Lock/Spring/Buffer Retainer Block/Bolt Rubber/Grip Screw
- WA M4 Dust Cover Set