Rock Island Armory STK100 Ultra 9mm, Full-Size, 4.49 in Barrel, Optics-Ready, 17+1, Black PECVD, 7075-T6 Aluminum Frame
The Rock Island Armory STK100 Ultra stands out as a full-size, striker-fired 9mm built on a 7075-T6 aluminum alloy frame with a black anodized finish. Its slide, barrel, and chassis wear a durable black PECVD coating, and the optics-ready slide includes adapter plates. Fixed white-dot sights co-witness with mounted optics, and the pistol features a flat-faced trigger, flared magwell, and a full-length dust cover with a 4-slot Picatinny rail.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Rifling Condition: Excellent - Sharp lands and grooves.
Specific Condition Notes: Minor scratching is present on the Picatinny rail where a light had previously been mounted. The chamber is clean, and the bore and rifling are bright and shiny.
What’s Included
- 1x 17-round magazine
- Aftermarket softcase
- RSH and RMSc optic adapter plates
- GTSG Stainless GRA recoil spring/guide rod assembly, 15 lb (Glock Gen 1-3 pattern), not installed
The Ultra variant of the STK series uses a 7075-T6 aluminum alloy frame that delivers a solid, full-size foundation and includes a flared magwell and textured integral grip panels. Its flat-faced trigger with integrated trigger safety supports a consistent striker-fired, recoil-operated action.
The slide, barrel, and chassis receive a black PECVD coating, with parkerized small parts for added corrosion resistance. The slide incorporates front and rear serrations for confident manipulation and an external extractor.
The optics-ready system uses a removable cover plate with an integrated rear sight. Fixed 3-dot sights (white front, two white rear) are designed to co-witness with mounted optics. RSH and RMSc adapter plates are included to support common micro red-dot footprints.
A non-threaded 4.49-inch barrel features conventional rifling with a 1:10-inch right-hand twist and six grooves. The full-length dust cover provides a 4-slot Picatinny rail for lights or accessories. Standard capacity is 17+1 rounds.
Proof and import markings read "APINTL-PAHRUMP NV ACP PHILIPPINES," reflecting Philippine manufacture and U.S. importation details for this STK-series release.