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.
weight stock to mount to a carbine rifle (6-positions
mil-spec or commercial tube) – This is our carbine skullaton stock
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
all .223 and .308 AR carbine style rifles
Strong Glass Filled Nylon
to replace and quick to install
4 out of the 6 positions on a mil-spec or commercial tube
in Black or Flat Dark Earth
buttstock for the carbine AR, weighing in at 9.5 ounces
to add our Cheek Piece: Cheek piece will add an additional 1? height
on cheek rest
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
To Existing Commercial and Mil-Spec Buffer Tubes
after Market Commercial Buffer Tubes that exceed 1.1172? diameter may not
- 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
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
Anti-Rattle Set Screw
Compatible Buffer Assemblies:
Mil-Spec Carbine Buffer Assembly
Commercial Carbine Buffer Assembly
- .308 Mil-Spec
Carbine Buffer Assembly
- .308 Commercial Carbine
The MBA-4 does not include the
following accessories, they can be purchased on our website separately in
the Accessories section:
Swivels (Side or Rear) Sold Separately, see below.
tightening the anti-rattle set screw, be careful not to over tighten as
the threaded insert may separate from the plastic stock body
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.
LENGTH OF PULL
LENGTH OF PULL
Flat Dark Earth