ESF is available in 4140 steel, phosphate coated ESF-H. ESF has rotation limited side facing sockets. The rear facing socket has no limiters, as the receiver extension effectively limits the swivel’s rotation.
4140 phosphate coated ESF-H is no light weight at 1.1oz. Our 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. Our concern with weight is only limited to keeping our 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 we deem its heft to be acceptable, given its immense strength.
As is our practice, 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.
Aesthetics were never a part of the stated objectives for ESF. Nonetheless, ESF, like similar products before it, effectively lengthens the carbine receiver’s rear and gives it a silhouette reminiscent of the classic AR10/SR25. We’ve long considered the AR carbine’s rear seems to be abruptly terminated, which leaves a gap between the end plate and the carbine’s retractable stock. ESF fills the void and, the classic AR15/M16 lines flow far better with it. Even though we take a dim view of fashion firearms and components, we can still appreciate aesthetics, especially if they stem from the design’s functions.