Spatha-15 Furniture and Controls Lower

Our lowers are assembled by SOTAR-trained master armorers in North Carolina using components manufactured exclusively in the USA.

The Spatha-15FC lower makes targeted improvements to the EM model intended to improve the ergonomics, operability, and reliability of an already great weapon system. These upgrades include:

• Everything Mil-Spec or Better
  • We build our lowers with true Mil-Spec or better components.  It is important to emphasize this because many claim to use Mil-Spec components, but use components made of inferior materials/quality.  We refuse to cut corners to save a buck.
• Buffer: Heavy (H1) Carbine Buffer
  • We use a heavy (H1) buffer in our EM and FC levels in the carbine series. The heavy buffer offers additional inertial resistance to the movement of the BCG out of battery, which increases the bolt lock time or “locked chamber dwell time” (which contributes to reliability and accuracy).
• Buffer Spring: David Tubb Flat Wire AR-15 Buffer Spring
  • The buffer spring is one of the most forgotten/neglected components of the AR, but is also one of the most important. The David Tubb Flat Wire Spring is is phenomenal upgrade, providing immediate improvement to the performance and longevity of the buffer system. The Tubb FWS offers additional closed bolt resistance (which increases the bolt lock time), and offers a more gradual and consistent increase in spring pressure through the cycle of the reciprocating mass.
• Buttstock: Magpul MOE Buttstock
  • The MOE carbine buttstock is probably one of the most recognized aftermarket upgrades, and for good reason. It improves the ergonomics and operability of the weapon system.
• Grip: ERGO 2 Suregrip Pistol Grip
  • The grip is your most tactile interface with the weapon. The ERGO 2 Suregrip has an ergonomic profile for all-day comfort and a rubberized and textured grip surface for confident manipulation in all conditions.
• Magazine Release Button: Odin Works XMR3 Extended Magazine Release Button
  • You’re gonna drop a mag every 30 rounds or so. When you do, you’re out of commission. Finding and engaging the mag release button stands between your last pew and your next pew. While practice is important, design of the magazine release button can help. For the FC and DC level, we move up to the Odin Works XMR3.
• Pivot/Takedown Pins: Battle Arms Development Steel Enhanced Pin Set
  • Pivot and takedown pins aren’t sexy and you may not use them often. But when you do, you want disassembly of the receivers to be a piece of cake. For the FC and DC levels, we upgrade the pins to Battle Arms Development pivot/takedown pins, which are slightly longer, have an improved grip surface, and have depressions on the left side of the receiver to aid in disengaging.
• Receiver Extension: Aero Precision Enhanced (Anti-Tilt) Carbine Receiver Extension
  • For the FC and DC levels in the carbine series, we upgrade to an anti-tilt receiver extension. This upgrade improves the alignment of the bolt carrier group in the upper receiver, which prevents unnecessary resistance, premature wear of the tube, and has a secondary benefit of anti-rotation functionality. Please note that, while we try to have a color-matched Aero Precision Enhanced buffer tube, we may substitute with a black Aero or black P.O.F. anti-tilt receiver extension, based on availability.
• Safety Selector: Radian Talon Ambidextrous Safety Selector
  • We like to be able to control our weapon from either side of the receiver. Most people do. For the FC and DC levels, we move up to the gold standard in safeties: the Radian Talon.
• Trigger: HIPERFIRE Enhanced Duty Trigger Heavy Gunner (EDTHG) Trigger
  • The trigger is an AR’s “go” button. While the Schmid trigger in our EM model is great, we see the trigger as one of the first controls to upgrade. In the FC model, we move up to the heavy-hitting HIPERFIRE EDTHG.

Critical finishes and dimensions of individual components are inspected before they we accept them into inventory.  To learn more about our quality control gauging and inspection, visit our Quality Promise page.

Each upper receiver includes the following assembly and QC steps (full schedule of all 82 points of inspection for our builds can be found in our Quality Promise page):

• Receiver extension (buffer tube) threads lubricated with AeroShell.
• Receiver extension castle nut torqued to 40 ft. lbs.
• Receiver extension castle nut properly staked in two locations.
• Trigger sear, hammer sear notch, hammer hook, and disconnector honed, as necessary.
• Full lubrication per our standard procedure.
• Full safety and function check per our standard procedure.
• Live fire test with 5 rounds of M193 or M855.

The tables below detail what we put in the lower and what you are paying.

Spatha-15FC Lower Receiver (Black)

Spatha-15FC Lower Receiver (FDE)