CORE 15 Custom 5.56 NATO AR-15 Rifle with 16" R Guns Barrel & Collapsible Stock
This full-size CORE 15 combines the proven AR-15 platform with a chrome-moly, 1:9-twist R Guns barrel and a six-position collapsible stock. Built by Good Time Outdoors prior to CORE Rifle Systems’ discontinuation, it offers Type III hard-coat anodized 7075-T6 receivers, a flat-top upper with T-marked rail, and an F-marked A2 front sight base. With its threaded M4-profile barrel and solid U.S. construction, this rifle delivers a ready-to-customize foundation for range or duty use.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: Minimal handling marks are visible on the receivers and stock; the bore remains bright and clean.
What’s Included
- CORE 15 semi-automatic rifle
- 2 polymer 10-round AR-15 magazines marked ".223 REM"
The heart of this rifle is a 16" chrome-moly R Guns barrel marked "5.56 NATO 1/9". It sports an M4 profile and is threaded 1/2-28 RH, giving you immediate compatibility with standard muzzle devices or suppressor mounts.
Both upper and lower receivers are forged from 7075-T6 aluminum and finished with Type III hard-coat anodizing for durability. The lower bears the distinctive "C XV" forging mark and bullet pictogram selector engravings, underscoring its CORE lineage.
The flat-top upper features laser-engraved T-index marks for repeatable optic placement. An F-marked A2 front sight base provides a solid front post, while the rail-ready upper lets you add the rear sight or optic of your choice.
A six-position collapsible stock—sporting the recognizable Spike’s Tactical spider logo—pairs with a polymer ribbed handguard for a comfortable, adaptable shooting stance. Direct-impingement operation keeps the rifle light and parts-compatible with standard AR components.
CORE Rifle Systems operated from 2009 into the late 2010s; with production now discontinued, this example offers a clean, lightly handled piece from a closed maker, enhanced by its aftermarket barrel and ready for further customization.