The release generated significant excitement across firearm communities (AR15.com forums, Reddit, X/Twitter, and more), with many calling it “sick,” “ridiculous in the best way,” and even comparing the aesthetic to video game weapons like the Fallout series assault rifle. It’s
frequently discussed alongside forced-reset and binary trigger setups for maximum fun factor.
The LIMA-1917 Complete Water Cooled Upper Kit from KAK Industry is an extraordinary piece of modern firearm engineering — a belt-fed AR-15 upper receiver in 5.56 caliber featuring genuine water-cooling for true sustained-fire capability. This marks one of the first times in years that a civilian-legal water-cooled belt-fed assembly has been offered commercially.
Priced at $4,999.95, this fully assembled drop-in upper is designed for enthusiasts who want to push the limits of semi-auto (or compatible full-auto setups) shooting without worrying about rapid barrel overheating.
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What Makes the Lima-1917 Stand Out?
Inspired by classic water-cooled machine guns like the M1917 Browning, KAK Industry has brought this concept into the AR-15 platform. The key innovation is the integrated water jacket surrounding the 18-inch barrel. As long as the jacket contains water, barrel temperatures stay capped at 212°F (boiling point) — even during prolonged rapid or sustained fire.
When the water eventually boils, steam is vented through a dedicated port and tube. A steam hose is included to connect to an optional condensing can (not included), allowing you to:
- Reduce visible steam signature
- Collect and reuse condensed water
Without the condensing setup, steam simply exits into the air (which may create a visible position-revealing plume during heavy use).
This upper builds on the air-cooled Lima-6 belt-fed design but adds the cooling system for dramatically improved heat management — perfect for high-volume range sessions, training, or fun “mag dump” scenarios.
Key Features & Specs
- Caliber: 5.56 NATO
- Barrel Length: 18 inches
- Cooling System: Water jacket with red fill plug (secured by wire lanyard)
- Sustained Fire: Designed for extended rapid/sustained shooting without excessive heat buildup
- Compatibility:
- Works with standard semi-auto AR-15 lowers
- Compatible with transferable or post-sample machine gun lowers
- May require tuning for forced-reset triggers (FRT) or super safeties (not guaranteed out-of-the-box)
- Sights: Fixed front sight; compatible with carry-handle, fixed, or flip-up rear sights (adjustable recommended for precise zero); standard-height red dots co-witness normally
- Included:
- Fully assembled water-cooled upper
- Buffer tube kit
- Modified bolt catch
- Steam hose for condensing setup
Important Practical Notes:
- No drain valve — After use, elevate the firearm and drain water through the fill hole
- Storage: Drain completely, dry, and apply WD-40 or CLP through the fill port for corrosion protection
- Barrel Service: Barrels are not user-swappable; return the upper to KAK for barrel replacement, O-ring service, etc. (fee applies)
This isn’t your average AR-15 upper — it’s a niche, high-end piece for collectors, belt-fed enthusiasts, range day warriors, and anyone who wants to experience sustained belt-fed fire on an AR platform without melting barrels. At nearly $5,000 (plus the cost of a compatible lower, ammo belts, and optional condensing gear), it’s a serious investment in unique shooting capability.
If you’re ready to level up from standard AR builds to something truly legendary, keep an eye on KAK Industry for restock alerts. The Lima-1917 proves innovation in the firearms space is alive and well — water-cooled belt-fed ARs are no longer just history! 🚀💦
