SPR/MK-12 Barrels 18.1 Criterion-CM


Length              18.1″
Caliber             .223/5.56
Gas Block        .750



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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