MSF 13.9 / 13.7 Pinned & Welded Ar-15 Rifle



Mid State Firearms Ar-15 Rifle, pinned & welded 13.9 with suppressor adapter muzzle device to reach 16″ legal length.


FFL Disclaimer

Before purchasing, please send a copy of the FFL to us at I understand that this item has to be shipped to an FFL.

Charging Handle Options

Handguard Options

Muzzle Device Options

Fits Specwar, Saker, Hybrid, Omega, Harvester ASR Mounting System

Tools / Extras

Product price: $1,199.00
Order total:

Free shipping on all orders over $500

  • Live inventory and ready to ship
  • Questions? Text us at (601) 720-8252

MSF premium series rifles ready to work. This Ar15 Rifle features a 13.9″ 4150CMV Barrel and a pinned and welded muzzle device to reach the legal 16″. We offer a variety of muzzle devices and suppressor adapters that you can choose from. The upper is paired with a MSF billet lower that has excellent ergonomics and a trigger assembly of your choice. We highly recommend the Velocity and Elftman single stage drop-in triggers.

Upper Features:

13.9″ Ar-15 5.56/223 Upper (Legal rifle, 16″+)

  • 13.9″ 4150 Chrome Moly (CMV) Barrel. (0.2 longer than 13.7″ for more muzzle device options).
  • 1:7 twist.
  • m4 feed ramps.
  • 556 NATO Chamber (shoots both 5.56 and 223).
  • Mid Length gas system
  • .750 Steel Low Profile Gas Block, barrel dimpled for gas block screw lockup.
  • Dust cover, Forward Assist installed.
  • Spectre Flash Hider (differs from A2).
  • 12″ Free Float M-Lok Handguard

M16 BCG & Charging Handle available in options. This comes professionally assembled and ready to go. If you order our BCG, we’ll test fire with that one prior to shipping.

  Muzzle device is pinned and welded to make a legal 16″+ upper.  Contact us for any questions regarding this that you may have.

Lower Features

The MSF billet lower features an enlarged trigger guard area and a flared magwell. Several custom options available, it is pictured with a 3.0 lb Velocity trigger, Roger’s superstock, Magpul MOE grip, and extended takedown/pivot pins.


We assemble everything in-house, completely customized to your order. Our engineers have many years of experience in the industry, making sure that everything that goes out the door is built to the highest standard possible.

Prior to shipping, we test fire and follow a strict quality control protocol, paying extra attention to the gas system and headspace, ensuring that your AR-15 will function properly and will reliably fire in all cases. 


Over the past 10 years, we have carefully refined the parts we use for our AR-15 uppers. We only use high-quality components in our builds that have been sourced from proven manufacturers and OEMs.

We have built tens of thousands of AR-15s and ensure reliability, durability, and accuracy in all of our products.


We stand behind our products and have a limited lifetime warranty on the uppers that we sell.  Our warranty protects against defects in product, material, or workmanship.

If there is an issue, simply contact us, and we will handle it. We will repair/replace items if necessary. 

Additional information

Weight 7 lbs
Dimensions 36 × 8 × 8 in