SLR-104UR SBR Quad-Rail

SLR-104UR SBR - 5.45x39.5mm caliber, Stamped receiver, short gas system, front sight block / gas block combination, polymer buttstock, Featuring Arsenal's Mil. Spec. Picatinny Quad-Rail System for attaching Lasers, Flashlights, and Optics..

  • MSRP $2,049.99
Not rated yet
  • Weight
    7 lbs
  • SKU
    SLR104-55R

SLR-104UR SBR - 5.45x39.5mm caliber, Stamped receiver, short gas system, front sight block / gas block combination, chrome lined hammer forged Short Barrel, cleaning rod, left-side folding black polymer buttstock, 2 stage trigger, and scope rail.

The PR-03 Picatinny Quad Rail Handguard System was designed and manufactured to meet and exceed the following stringent military requirements:

  • Ability to accept cleaning rod with the rail system installed – achieved with stainless steel internal guide rail
  • To easily align the rail system with both milled and stamped receivers – achieved with a pair of precision machined tabs
  • Ability to constrain debris from entering into the receiver from under-rail openings – achieved with sealing caps of the rail system
  • Minimize weight, while providing maximum strength – achieved with the triangular support design and utilizing aircraft grade durable aluminum material
  • Providing the maximum number of rails – achieved with optimum design with 14 rails on the bottom and the sides, and 9 rails on the top
  • Identification marks for repeat attachment of devices – achieved with clearly marked numbering system on all 4 sides
  • Provide comfortable grip to the shooter – achieved with compact system profile and smooth finish

Picatinny Quad-Rail System for attaching Lasers, Flashlights, and Optics.



  • Manufacturer
    Arsenal Inc.
  • Caliber:
    5.45 x 39 mm
  • Total length:
    28 7/8 in. (733 mm)
  • Folded length:
    19.37 in. (492 mm)
  • Barrel length:
    8.5 in. (216 mm)
  • Rifling:
    4 grooves
  • Twist rate:
    1:7.8 (1 in 200 mm)
  • Weight w/o magazine:
    6.1 lbs
  • Muzzle velocity:
    2,953 fps (900 m/s)
  • Effective range:
    500 m (547 yds)
  • Maximum range:
    1350 m (1,480 yds)
  • Rear sight range:
    500 m (547 yds)
  • Rate of Fire:
    40 rds/min (practical)

You can purchase our products from our distributors, at your local dealers, or online at www.k-var.com.

California Proposition 65

WARNING: None of the firearms manufactured or imported by Arsenal Inc. are manufactured or imported with the intent to be sold in CA.  Nevertheless, be advised that some products sold on this website and/or manufactured by Arsenal Inc. can expose you to chemicals, including lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to  www.P65Warnings.ca.gov.