Strike Industries Viper Modular AR Fixed Stock

Strike Industries Viper Modular AR Fixed Stock

Product Code:
Calculated at Checkout
$35.95 $33.95



  • Customizable Length of Pull (12" to 14.25") with included shim set
  • Combines the versatility and adjustability of a collapsible stock with the strength, ergonomics, and solid fit of a fixed stock
  • Modular assembly
  • HK Hook attachment and sling loop
  • Install on carbine-length / A5 buffer tubes
  • Available in Black and Flat Dark Earth finish!
  • Compatible with Strike Industries Viper MFS Extended Rubber Butt Pad and Viper MFS Monopod (Optional)





  • Weight: 12.63 oz. (with mounting hardware and shim set)
  • Material:
    • Stock: Polymer
    • Mounting Hardware: Steel
  • Length:
    • Min: 9"
    • Max: 11.25"
  • Height: 5.13"
  • Width: 1.75"


  • Mil-Spec carbine-length and A5-length buffer tubes


  • 1x Viper Modular Fixed Stock
  • 1x Stock Front Piece
  • 3x Adjustment Shims (0.75-inch)
  • 1x Carbine-Length / A5 Buffer Tube Adapter
  • 1x Adapter Screw


If you’re a fan of the personal defense or close quarters Viper stock and you need an AR-15 Fixed Stock, Strike Industries has heard your cries. The Viper Modular Fixed Stock brings options for versatility and adjustability to the table along with the solid fitment, ergonomics, and hardiness of a fixed stock.

Fixed Stock, Custom Pull Length

The Strike Industries Viper Fixed Stock accepts standard carbine length receiver extensions. When you need an AR fixed stock for an existing weapon, it’s no problem to fit an SI Viper MFS. All you need to do is choose your desired length, install the correct spacing shims and you will have a custom length of pull and an AR-15 Fixed Stock that holds rock solid even under extreme operating conditions. As packaged the Viper MFS is easy to customize in ¾-inch increments from 12 inches to 14.25 inches length of pull.

Polymer Construction with the Security of Steel

The Strike Industries Viper Modular Fixed Stock features the light weight of a polymer AR Fixed stock with the security or quality steel mounting hardware. Strike delivers exactly what you need. Fit, feel, and reliability without compromise.

Field Ready Design

The field ready design of the Strike Industries Viper Modular Fixed Stock requires no additional sling mounting hardware. It features an integrated HK hook Attachment and sling loop. Since you’re working with a solid stock you won’t have to quiet odd rattles when you’re on the move and there’s no worry about catching a latch and pulling up at the wrong length. Simply mount the SI Viper MFS up at your desired length, clip on your favorite sling and you’re mobile, ready for whatever the next maneuver brings.


  1. Slide the front piece onto the carbine-length buffer tube until it touches the castle nut
  2. Install the buffer tube adapter on the first slot of the buffer tube
  3. Add adjustment shims if needed
  4. Install the Viper Modular Fixed Stock onto the buffer tube
  5. Remove the rubber butt pad
  6. Use the adapter screw to secure the stock
Write a Review

4 Reviews

  • Viper modular fixed stock

    Posted by Richard on 18th Jan 2019

    This stock is great and doesnt break the bank. Loving how you u can adjust the lenght with spacers for your comfort. I compete in compitetions and living in cali were we cant have adjustable stocks anymore this stock benefits me having it to the lenght of my comfort when running the course.

  • Iooks great

    Posted by Paul e henderson on 10th Jan 2019

    Easy to mount on ar ,no buffer tube or spring to change on my carbine ,just slide it on tighten it up and your ready to shoot.very simple.

  • Great fit

    Posted by David on 7th Jan 2019

    Would buy another

  • Good fit

    Posted by Josh on 16th May 2018

    Good product good sis good price good But needs qd cup

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