Winchester USA M855 Green Tip (WM855K) is a 5.56x45mm NATO centerfire rifle cartridge loaded to military SS109 specification, built for AR-platform shooters, competitive shooters, and high-volume range trainers who want mil-spec performance, brass cases, and a proven green tip penetrator bullet in a 20-round box packaged 50 boxes to the case.
Key Features
- Manufacturer Part Number: WM855K (UPC 020892228474)
- Caliber: 5.56x45mm NATO
- Bullet Type: Full metal jacket, boat tail, green tip penetrator
- Bullet Weight: 62 grains
- Bullet Construction: Lead core with 7-grain mild steel penetrator at tip, copper jacket
- Muzzle Velocity: 3,060 fps
- Muzzle Energy: 1,289 ft-lbs
- Ballistic Coefficient: .349
- Cartridge Length: 2.258 inches
- Case Material: Brass, reloadable
- Primer: Boxer
- Rounds Per Box: 20
- Boxes Per Case: 50 (1,000 rounds total)
- Made in USA
Special Features
- Winchester loads the WM855K to SS109 mil-spec standards, the same specification used for military issue 5.56 NATO ammunition, giving shooters a round built to documented performance and pressure requirements rather than a commercial approximation.
- The brass cases are headstamped and Boxer primed, making them fully compatible with standard reloading dies and allowing experienced reloaders to reclaim and reload fired brass from the range.
- The 7-grain mild steel penetrator behind the green-painted tip is seated at the bullet's core forward section, increasing the projectile's overall length and raising the ballistic coefficient to .349, which improves wind resistance and retained velocity compared to the lighter 55-grain M193 bullet.
- The full metal jacket copper jacket fully encases the lead core and steel penetrator, ensuring smooth, reliable feeding through semi-automatic AR-platform rifles and minimizing lead fouling in the bore across high round count sessions.
- At close-range velocities, the M855 bullet tends to fracture at the cannelure into two or three main pieces, a design behavior that delivers expanded terminal effect beyond what a non-penetrator FMJ achieves at shorter distances.
- The 50-box case format packages 1,000 rounds in a single purchase, making the WM855K an efficient buy for range trainers, competitive shooters, and stores who want to minimize per-round cost on volume purchases.
Practical Benefits
- The 62-grain bullet weight and 1-in-7 or 1-in-8 inch twist barrels found on most modern AR-15s are well matched, giving you stable, consistent flight and reliable accuracy at ranges out to 500 meters.
- The mil-spec SS109 loading means you get the same round profile your AR-platform was engineered to feed and cycle, making the WM855K a low-risk choice for reliable semi-automatic function across a wide range of AR builds.
- The brass cases eject cleanly and hold up to multiple reloading cycles, so if you reload your own ammunition, your range pickups from this cartridge go straight back into the reloading room rather than the scrap bucket.
- Buying by the case at 1,000 rounds reduces your cost per round and ensures you have enough ammunition on hand for extended training sessions, competition matches, or store inventory without repeated small-quantity reorders.
- The green tip is a visual indicator that confirms round type at a glance during loading, sorting, and range use, a practical detail that matters when you are managing multiple calibers or bullet types at the bench.
- If you shoot an AR-15 or any 5.56 NATO rifle and want a high-volume, mil-spec training round with brass cases you can reload and a documented penetrator construction, the Winchester USA M855 Green Tip (WM855K) gives you that combination in a 1,000-round case.
The Winchester USA M855 Green Tip (WM855K) in 5.56x45mm NATO is a dependable option for the AR-platform shooter, competitive trainer, or retailer stocking a proven mil-spec green tip round with reloadable brass cases and consistent performance from the first box to the last.
| MANUFACTURER | WINCHESTER |
| CALIBER | 5.56MM |