Last reviewed: 2026-04-19 by Jake Terry, FFL07/SOT3, NRA-certified firearms instructor.
The Winchester M193 5.56 NATO 55gr FMJ is a full-metal-jacket cartridge chambered in 5.56x45mm NATO, built for high-volume training, target work, and range sessions where reliability and consistent performance matter more than terminal expansion. This load replicates military M193 ball specifications — 55 grains at 3180 feet per second from a 20-inch barrel — delivering 1235 foot-pounds of muzzle energy with minimal barrel erosion and predictable point-of-impact across standard AR-15 and M4 platforms. Each case is boxer-primed, non-corrosive, and reloadable, manufactured in the United States by Winchester under ISO-certified processes.
Performance at a Glance
Winchester loads this cartridge with a 55-grain full-metal-jacket projectile — a copper-jacketed lead-core design that does not expand on impact. The FMJ construction feeds reliably in semi-automatic actions, resists deformation during magazine storage, and produces minimal fouling in gas systems. Muzzle velocity of 3180 fps is measured from a 20-inch test barrel; expect approximately 3000-3050 fps from a 16-inch carbine and 2900-2950 fps from a 14.5-inch M4-profile barrel. Muzzle energy of 1235 foot-pounds drops to roughly 1100 ft-lbs at 100 yards and 900 ft-lbs at 200 yards, maintaining sufficient momentum for target penetration at typical range distances.
| Spec | Value |
|---|---|
| Caliber | 5.56x45mm NATO |
| Bullet weight | 55 grains |
| Bullet type | Full Metal Jacket |
| Muzzle velocity | 3180 fps |
| Muzzle energy | 1235 ft-lbs |
| Rounds/box | 1000 (50 boxes of 20) |
| Case | Brass |
| Primer | Boxer |
| Corrosive | No |
| Reloadable | Yes |
| Intended use | Range & Target |
| Manufacturer | Winchester |
This load is packaged in 50 boxes of 20 rounds — 1000 rounds total — with a shipping weight of 27.335 pounds. Brass cases are dimensionally consistent for reliable extraction and ejection in mil-spec chambers. Primer pockets accept standard small rifle primers for handloaders. For additional 5.56 NATO loads and bulk options, browse our full Winchester 5.56×45 ammo selection.
Safe Handling & Compliance
Federal law requires purchasers to be at least 18 years old for rifle and shotgun ammunition, and at least 21 for handgun ammunition. Ammunition cannot be shipped to certain states, counties, and cities — review our ammunition shipping restrictions before ordering. Store ammunition in a cool, dry location away from heat sources and out of reach of unauthorized users.
- Always follow the four rules of firearm safety when handling live ammunition.
- This product contains lead, a chemical known to the State of California to cause cancer and birth defects or other reproductive harm — store and handle in well-ventilated areas.
- Verify that your firearm is chambered for 5.56x45mm NATO before loading — do not fire 5.56 NATO ammunition in chambers marked “.223 Remington only.”
Reviews
There are no reviews yet.