Luth-AR MBA-4F Skullaton Stock - Black

Your Price: £79.99
Out of Stock.
Part Number:T73

The Luth-AR Modular Buttstock Assembly (MBA) for AR style carbines is designed to replace the standard buttstock on your AR. The MBA-4 is designed to work with a 6-position Mil-Spec or Commercial buffer tube. The MBA-4 is a direct replacement a standard adjustable carbine buttstock without additional Length-of-Pull or Cheek rise in a low-cost, lightweight, strong and high-quality design.

The MBA-4 requires a Carbine buffer tube, either Mil-Spec or Commercial. Please review the information provided in the Requirements tab. This stock works with both carbine Commercial and Mil-Spec tubes/assemblies.

The MBA-4 also features an anti-rattle set screw. The modular design of the MBA Buttstock allows you to configure your buttstock to your specific and personal needs. The MBA features multiple attachment points for a sling, including molded pockets that will accept Grovtec QD cups, sold separately. Available in Black or Flat Dark Earth.

Product Description

  • Light weight stock to mount to a carbine rifle  (6-positions mil-spec or commercial tube) – This is our carbine skullaton stock
  • The MBA-4 requires a Carbine buffer tube, either Mil-Spec or Commercial. Please review the information provided in the Requirements tab. This stock works with both carbine Commercial and Mil-Spec tubes/assemblies.
  • Fits all .223 and .308 AR carbine style rifles
  • Super Strong Glass Filled Nylon
  • 21st century look
  • Ergonomic
  • Easy to replace and quick to install
  • Uses 4 out of the 6 positions on a mil-spec or commercial tube


  • Available in Black or Flat Dark Earth
  • Lightweight buttstock for the carbine AR, weighing in at 9.5 ounces
  • Easy to add our Cheek Piece: Cheek piece will add an additional 1? height on cheek rest
  • Easy to add our Butt Plate Assembly or 3-Axis Butt Plate Assembly: The assemblies will add an additional 1 1/16? length of pull with extended length buttplate
  • Adapts To Existing Commercial and Mil-Spec Buffer Tubes
  • Certain after Market Commercial Buffer Tubes that exceed 1.1172? diameter may not fit
  • Caution: the MBA-3 and MBA-4 Carbine buttstocks are not designed to be used with Large Bore Calibers such as .338 Lapua or .50 BMG applications. See our MBA-1 and MBA-2 Rifle buttstocks as alternatives
  • The MBA-4 Carbine buttstock is NOT interchangeable with A2 standard buffer tube. You will need to purchase a MBA-1 or MBA-2 Rifle buttstock to fit A2 tubes 


  • Picatinny Rail
  • Revolutionary Anti-Rattle Set Screw

Compatible Buffer Assemblies:

  • .223 Mil-Spec Carbine Buffer Assembly
  • .223 Commercial Carbine Buffer Assembly
  • .308 Mil-Spec Carbine Buffer Assembly
  • .308 Commercial Carbine Buffer Assembly

Additional Information

The MBA-4 does not include the following accessories, they can be purchased on our website separately in the Accessories section:

  • Sling Swivels (Side or Rear) Sold Separately, see below.
  • Carbine Buffer tube
  • Carbine Buffer Body
  • Carbine Spring
  • Latch Plate
  • Lock Ring

Installation Notes:  

  • When tightening the anti-rattle set screw, be careful not to over tighten as the threaded insert may separate from the plastic stock body
  • When sliding the buttstock onto a 6-position buffer tube, the lock pin has a notch in the head of the lock pin that must line up with a tab on the stock body. Once the slot and tab are lined up, the pin can be fully retracted allowing the buttstock to slide onto the tube. The MBA-4 should slide easily without resistance. If there is any resistance, the lock pin is not fully retracted. 

Luth-AR Note on Savage Rifles:

Our MBA-4 is designed to fit standard Mil-Spec and Commercial Tubes. Some Savage tubes have been found to be oversized making our stock fit very tightly. Please note that you may need to simply purchase a standard carbine tube in order for this to pair correctly. Note: Customers have reported that the MBA-3 or MBA-4 fit the buffer tube that comes on the new model 110 BA Stealth. If you have the older model 110 BA you may have to simply change the buffer tube.

SKU: MBA4-B — Black

SKU: MBA4-FD — Flat Dark Earth

Buffer Tube Requirements

The MBA-3 and MBA-4 are Carbine Buttstock and requires the use of a Carbine buffer tube. The MBA-3 and MBA-4 will fit either a Mil-Spec or a Commercial buffer tube. (Note: Some commercial buffer tubes may be oversized from industry norms and may not fit. All commercial buffer tubes sold by Luth-AR will fit the MBA-3 and MBA-4).

Carbine buffer tubes typically have 6 positions of adjustability, and can be distinguished from an A2 style Rifle buffer tube that offers no adjustment positions. Carbine buffer tubes also differ from the A2 by their shape, the A2 Rifle buffer tube is completely round in shape while the carbine buffer tubes have a rectangular appendage to the tube that encloses six position holes. An A2 Rifle buffer tube is substantially longer than a carbine buffer tube.

Carbine buffer tubes typically are offered in two types, Mil-Spec or Commercial. The Mil-Spec carbine buffer tube is visually identified by the 90 degree “cut” at the closed end of the tube. The Commercial carbine buffer tube is visually identified by the 6 degree slant “cut” at the closed end of the tube. A Mil-Spec tube should meet Military Specifications while Commercial tube dimensions are determined by the manufacturer and are typically made from an extrusion. As long as a Commercial buffer tube does not exceed 1.172? in diameter the MBA-3 and MBA-4 should fit the buffer tube. Using a Commercial buffer tube with an MBA-3 and MBA-4 will typically provide a more “snug” fit due to the slightly larger diameter of Commercial buffer tubes.






.223, .308


9.6 oz


15 1/8"


11 5/8"


7 1/2"






Black, Flat Dark Earth

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