Spartan S3 Upper from Zel Custom

Spartan S3

Zel Custom has a new upper for the AR-10 and LR-308 platforms called the Spartan S3.  The Spartan S3 is a bolt action upper that allows an owner to shoot .50 BMG, .416 Barrett and .338 Lapua.  This upper is similar to other uppers by Zel Custom (and other manufacturers) that allow the shooting of heavy calibers from am AR-15 lower.

The Spartan S3 uppers can be had with either Mossberg or Lothar Walther barrels in lengths ranging from 18.5″ to 32″.  Pricing starts at $1,898 and goes up depending on options selected.

The upper shown in the photo above is unfinished, but various finishes are available including parkerizing, ferritic nitrocarburizing, and CeraKote.

Richard Johnson

An advocate of gun proliferation zones, Richard is a long time shooter, former cop and internet entrepreneur. Among the many places he calls home is


  • Paul Epstein

    Needs pictures. As shallow as it seems, a lot of the time decisions to purchase items in the firearms community are not made based on which marginal improvement in performance a particular item makes, but on whether it enhances their ability to show off to their friends and family.

    Not catering to that means that luxury items like .50 BMG rifles, which will *never* be used for any practical purpose, will fall by the wayside.

  • FourString

    Is it single shot or magazine fed? Can’t tell from description :/ but I’m guessing single shot?

    • gunslinger

      website doesn’t indicate any magazine specs. i would also guess a single shot.

  • Aaron E

    Not that I’m in the market for a $2000 upper to shoot calibers that cost $2-5 per round, but I would be interested in seeing the accuracy. Many AR-15’s have some play between the upper and lower receivers. Most of the highly accurate long range rifles use free-float barrels attached to pillar bedded receivers for a very tight fit.

    Not sure how much play there will be between the Spartan S3 and an AR-15 lower, and how much that will affect accuracy.