SPR/MK-12 Barrels 17.9″ Criterion-CM


Length              17.9″
Caliber             .223/5.56
Gas Block        .750

  • 1-7 Twist
  • 1-8 Twist
  • MID Length
  • Intermediate Length
  • 1/2x28
  • 5/8x24
  • None
  • Add Matched Bolt
  • Customer Supplied


This barrel comes standard with M4 Feed Ramps, MID or Intermediate gas system, 1/2-28 or 5/8×24 threaded muzzle, and the proper OPS, Inc. muzzle contour for OPS, Inc. collar.

Chamber type, gas system , thread and match bolt is your choice.

Please Note, barrels are finished to your specs after you order them. Currently, we are at about 3-4 weeks turn around for SPR barrels. We do hit delays from time to time and it may take an additional week.


Additional information



Gas System Length




Matched Bolt

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