Last reviewed: 2026-04-19 by Jake Terry, FFL07/SOT3, NRA-certified firearms instructor.
When you need 300 AAC Blackout ammo that cycles reliably in AR-platform rifles and delivers consistent point-of-impact across high-volume range sessions, Winchester’s White Box USA line stands ready. This 125-grain jacketed hollow point load exits the barrel at 2185 feet per second with 1325 foot-pounds of muzzle energy — a supersonic velocity profile that produces audible feedback downrange and reliable function in carbine-length gas systems. 300 AAC Blackout is a bottlenecked intermediate cartridge designed to deliver .30-caliber performance from standard AR-15 magazines and bolt carrier groups, offering shooters the ability to switch calibers without changing lower receivers or magazines.
Built for the Box
Winchester loads the White Box USA series with modern propellants engineered to reduce barrel fouling and maintain velocity consistency shot-to-shot. The 125-grain jacketed hollow point projectile pairs a copper jacket with an open tip design, allowing controlled expansion on soft targets while maintaining structural integrity during feeding and chambering. Brass cases carry Boxer primers, making every fired case reloadable for handloaders seeking to develop custom loads. Non-corrosive primers and powders extend barrel life and eliminate post-session neutralization protocols required by surplus corrosive ammunition.
Performance at a Glance
| Spec | Value |
|---|---|
| Caliber | 300 AAC Blackout (7.62x35mm) |
| Bullet weight | 125 grains |
| Bullet type | Jacketed Hollow Point (JHP) |
| Muzzle velocity | 2185 fps |
| Muzzle energy | 1325 ft-lbs |
| Rounds/box | 200 (10 boxes of 20) |
| Case | Brass |
| Primer | Boxer, non-corrosive |
| Reloadable | Yes |
| Velocity rating | Supersonic |
| Intended use | Range & Target |
| Manufacturer | Winchester |
The 2185 fps velocity rating places this load well above the 1125 fps sound barrier, ensuring bolt lock-back and reliable ejection in both carbine and pistol-length gas systems. Shooters running adjustable gas blocks should start with standard settings before fine-tuning for this load’s pressure curve. This 200-round bulk pack delivers 10 individual 20-round boxes, allowing you to stage ammunition in range bags or store unused boxes in climate-controlled environments. Explore the full 300 Blackout ammo selection for subsonic and barrier-blind alternatives.
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.
- Observe the four rules of firearm safety — treat every firearm as loaded, never point at anything you are not willing to destroy, keep your finger off the trigger until sights are on target, and identify your target and what lies beyond it.
- Verify current state and local ammunition laws before ordering — some jurisdictions restrict hollow-point ammunition or require background checks at time of purchase.
- This ammunition contains lead, a substance known to the State of California to cause cancer and reproductive harm under Proposition 65 — wash hands thoroughly after handling.
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