MPN: IC-S2BD-556 / IC-S2C4-556 / IC-S2CH-556 / IC-S2NE-556 / IC-S2RG-556


  • Drop-in ready standard weight bolt carrier group
  • Advance coating provides excellent wear resistance
  • Heat treated, shot peened and Magnetic Particle Inspected (MPI)
  • Competition like performance with AK47 reliability
  • Easier to clean
  • Low coefficient of friction
  • Harder and stronger


  • Caliber: 5.56 NATO / .223 Rem / 300 Blackout
  • Material:
    • Bolt: Carpenter 158 Steel
    • Carrier: 8620 Case-Hardening Steel
  • Weight: 10.4 oz.
  • Finish:
    • BlackDiamond (Gloss Black): High Performance DLC
    • Copperhead (Gloss Rose Gold): Copper PVD TiCN
    • Ranger Grey (Gloss Grey): Nanocomposite PVD
    • C4V (Gloss Gold): PVD TiN
    • Nitride Elite (Matte Black): Black Nitride
  • Surface Hardness:
    • BlackDiamond: 3000 Vickers
    • Copperhead: 3200 Vickers
    • Ranger Grey: 3200 Vickers
    • C4V: 2600 Vickers
    • Nitride Elite: 715 Vickers
  • Coefficient of Friction:
    • BlackDiamond: 0.01
    • Copperhead: 0.1
    • Ranger Grey: 0.2
    • C4V: 0.4
    • Nitride Elite: N/A
  • Profile: M16

**A full-auto (A.K.A. M16) bolt carrier installed in a standard semi-auto AR-15 will not make the gun fire full-auto.


  • AR-15


  • 1x Bolt Assembly
  • 1x Cam Pin
  • 1x S2 Bolt Carrier
  • 1x Carrier Gas Key
  • 1x Firing Pin
  • 1x Firing Pin Retaining Pin


Whether you’re building a new AR-15 or you’ve decided to upgrade the bolt carrier group in an existing rifle, you’ll find a lot of offerings out there that have great features, but a lot of the cutting-edge coatings and attention to detail are reserved for the guys who are working with low mass systems. Iron City Rifle Works knows that not everyone needs an ultra-light AR, but every shooter deserves access to great quality components. If you need a standard weight bolt carrier group and want great performance and next-generation coating choices, Iron City Rifle Works’ S2 Drop-in 556 Bolt Carrier Group is going to make your wishes come true.

Superior Craftsmanship in a Standard Weight 556 Bolt Carrier Group

Finally, you don’t have to commit to a low mass bolt carrier group and all of the system adjustments that come with it in order to get the quality manufacturing and low friction coatings the low-mass competition circles have come to expect. When you choose an Iron City BCG you can expect a quality component group that leaves nothing to chance. Whether you choose your S2 Iron City BCG in BlackDiamond, C4V, or the Black Nitride coating, you’re going to get a quality bolt carrier group that features flawless machining and an advanced coating that will put the Mil-spec offering you’ve looked at to shame. Make your choice based on aesthetics or choose one of these coatings based on its level of inherent self-lubricity. That part is up to you, but either way, you’re going to be way ahead of the curve.

Less Lube, Less Fouling, Easier Cleaning

Iron City Rifle Works’ advanced coatings offer several advantages. First off, the inherent self-lubricity means you won’t need to constantly add extra lube to keep things moving freely. Any one of these coatings is far smoother and longer wearing than the traditional coatings you might be used to before you ever add a drop of lubricant. These ultra-slick surfaces reduce wear on those moving parts and collect less grime. Carbon fouling is easier to clean away than you’d ever believe until you try it yourself, and with less lube to catch grime and a super slippery surface to boot, there isn’t much for dirt and soot to cling to.

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