ESF (End plate, Sling Adapter, Forward Controls Design) is a drop-in end plate replacement for the AR platform (both 223 and 308 spec). Featuring three quick detach sling swivel sockets (two sides, and one rear-facing) when used in conjunction with a castle nut, ESF will allow retractable carbine stocks to fully collapse. SOPMOD and B5 Systems Bravo stocks will fully collapse with a rear-facing QD swivel installed, other carbine stocks must be closed on the #2 position on the RE (#1 position being fully closed) if a rear-facing QD swivel is present.
ESF-H has rotation-limited side-facing sockets. The rear-facing socket has no limiters, as the receiver extension effectively limits the swivel’s rotation.
FCD’s design philosophy focuses on utility, simplicity, and durability. 4140 ESF-H is heavy, because it is practically bomb-proof, and will outlast the 7075 aluminum receivers. FCD’s concern with weight is only limited to keeping their designs as close to TDP weight as possible. There isn’t a TDP equivalent for the ESF, and the 4140 ESF-H’s weight is centered on the AR, it will not cause the weapon to be front or rear heavy, thus FCD deems its heft to be acceptable, given its immense strength.
ESF’s shape is dictated by its functions. In order to accommodate the rear-facing socket, and fill one of the design requirements that ESF must be able to use stakable castle nuts and allow the carbine stock to fully collapse, ESF has a slight increase in width on the sides and small openings on the top of the sockets housing. These design cues do not affect ESF’s structural integrity, and mostly go unnoticed by users, they merely reflect a paradox, that it can be quite complicated to create a simplified design. A seemingly simple product can often be more than meets the eye.
End plates that incorporate side-facing QD swivel sockets can mask available wrench notches required for torquing. A conventional castle nut wrench has 3 lugs, in some cases, the socket housing may partially block access to one of them. A 2 lug castle nut wrench, such as the AR Multitasker, or our JCW (Joint Castle nut Wrench) would be required to torque the castle nut properly.
ESF does not ship with CNF (castle nut).
- Machined from 4140 steel.
- Weight: 1.1 oz.
- 3 QD swivel sockets.
- Made in the USA.