Winchester loads both classic military specs, M193 and M855, and that shapes its civilian lineup. Most Winchester 5.56 ammo falls into three buckets: 55-grain ball, 62-grain green tip, and a short list of specialty loads for defense and match work. Pick the bucket first, then pick the pack size. That’s really all there is to it.
Below we cover each Winchester 5.56 load at Bulk Ammo Vault, what it’s for, and how the listed numbers compare. Velocity and energy come from our catalog’s factory figures.
Bucket One: 55-Grain Ball (M193 and White Box)
This is the classic AR-15 range round. It uses a 55-grain FMJ bullet with a lead core.
| Load | Bullet | Grain | Velocity | Energy | Pack |
|---|---|---|---|---|---|
| Winchester 5.56 55 Grain FMJ White Box | Full Metal Jacket | 55 | 3,270 fps | 1,306 ft-lbs | 1,000-round case (50 x 20) |
| Winchester White Box 5.56 55 Grain FMJ | Full Metal Jacket | 55 | 3,270 fps | 1,306 ft-lbs | 1,000-round case (50 x 20) |
| Winchester M193 1000 Rounds 5.56 55 Grain FMJ | Full Metal Jacket | 55 | 3,180 fps | 1,235 ft-lbs | 1,000-round case (50 x 20) |
| Winchester M193 5.56 55 Grain FMJ | Full Metal Jacket | 55 | 3,180 fps | 1,235 ft-lbs | 1,000-round case (50 x 20) |
| Winchester M193 Ammo Can 5.56 55 Grain FMJ | Full Metal Jacket | 55 | 3,180 fps | 1,235 ft-lbs | 300-round ammo can |
| Winchester M193 300 Rounds 5.56 55 Grain FMJ | Full Metal Jacket | 55 | 3,180 fps | 1,235 ft-lbs | 300-round ammo can |
| Winchester White Box M193 5.56 55 Grain | Full Metal Jacket (M193) | 55 | 3,180 fps | 1,235 ft-lbs | 200-round value pack |
| Winchester M193 Value Pack 5.56 55 Grain FMJ | Full Metal Jacket | 55 | 3,180 fps | 1,235 ft-lbs | 200-round value pack |
| Winchester Valor 5.56 55 Grain FMJ | Full Metal Jacket | 55 | not listed | not listed | 125-round pack |
Winchester sells two flavors here. The White Box 5.56 55 Grain FMJ 1,000 Rounds lists 3,270 fps and 1,306 ft-lbs. The Winchester M193 1,000 Rounds lists 3,180 fps and 1,235 ft-lbs. Both are brass-cased, non-corrosive and loaded to 5.56 pressure. M193 is built to the military ball spec. White Box is Winchester’s own commercial 5.56 load.
For most shooters, the difference won’t show on paper at 100 yards. Buy whichever pack fits your plans. Learn more in our M193 ammo guide.
Bucket Two: 62-Grain Green Tip and Penetrator
M855 uses a 62-grain bullet with a steel penetrator under the jacket. The tip is painted green so you can spot it. Winchester also sells similar 62-grain penetrator loads under the Valor name.
| Load | Bullet | Grain | Velocity | Energy | Pack |
|---|---|---|---|---|---|
| Winchester M855 5.56 62 Grain Green Tip FMJ | Penetrator Full Metal Jacket | 62 | 3,060 fps | 1,289 ft-lbs | 1,000-round case (50 x 20) |
| SS109 Projectiles Loaded in Winchester M855 5.56 62 Grain | Penetrator Full Metal Jacket (SS109/M855) | 62 | 3,060 fps | 1,289 ft-lbs | 1,000-round case (50 x 20) |
| Winchester 5.56 62 Grain Penetrator FMJ | Penetrator Full Metal Jacket | 62 | 3,100 fps | 1,323 ft-lbs | 600 rounds (4 x 150) |
| Winchester USA Valor 5.56 62 Grain Penetrator FMJ | Penetrator Full Metal Jacket | 62 | 3,100 fps | 1,323 ft-lbs | 125-round pack |
The Winchester M855 62 Grain Green Tip 1,000 Round Case lists 3,060 fps and 1,289 ft-lbs. The Winchester 62 Grain Penetrator 600 Rounds and USA Valor 62 Grain Penetrator list 3,100 fps.
Keep two things in mind:
- Many indoor ranges do not allow steel-core ammo. Call ahead.
- Steel cores can damage steel targets. Use them on paper or at a safe distance from rated steel.
Our M855 green tip ammo guide goes deeper on this round.
Bucket Three: Defense and Match
Winchester Defender 64 Grain Bonded JHP
The Winchester Defender 5.56 64 Grain Bonded JHP is the defense load in the lineup. It lists 2,800 fps and 1,115 ft-lbs. Bonding locks the lead core to the jacket. That helps the bullet hold together after it opens. A heavier 64-grain bullet also tends to push deeper than a light varmint bullet. Laws on defense ammo vary, so check your state and local rules.
Winchester Match 77 Grain Sierra MatchKing
The Winchester Match 5.56 77 Grain Sierra MatchKing is for precision shooting. It lists 2,750 fps and 1,293 ft-lbs. The long 77-grain bullet needs a fast twist, usually 1:7 or 1:8. In those barrels, it’s a strong choice for long-range targets.
Picking the Right Pack Size
Winchester 5.56 ammo comes in many pack styles. Here’s how to think about them:
- 1,000-round cases give you the most rounds from one lot. That’s great for zeroing once and shooting a long time.
- 300-round ammo cans store well and carry easily.
- 200-round value packs fit a range day or a class.
- 125-round Valor packs and 20-round boxes are good for testing a load before you buy more.
Chamber Check: 5.56 vs 223
All the loads on this page are 5.56 NATO. Fire them only in rifles chambered for 5.56 NATO or 223 Wylde. A rifle marked only 223 Remington should not fire 5.56. If your rifle is a 223-only bolt gun, see our Winchester 223 ammo guide instead.
Most AR-15 rifles sold today are marked 5.56 or 223 Wylde, but always read your barrel. The stamp is usually near the muzzle or under the handguard.
Quick Answers by Use
- High-volume training: M193 or White Box 55-grain.
- NATO-spec practice with a heavier bullet: M855 62-grain, where your range allows it.
- Home defense: Defender 64-grain bonded JHP.
- Precision: Match 77-grain.
- Hunting: FMJ is not a hunting bullet, and many states ban it for big game. Choose an expanding load and check your state’s rules.
Shop Winchester 5.56 Ammo
Browse the whole lineup in our Winchester 5.56 ammo category, or compare every brand in 5.56 ammo. Pick your bucket, pick your pack, and get back to the range with Winchester 5.56 ammo you trust.
Frequently Asked Questions
What is the difference between Winchester M193 and White Box 5.56?
Both use a 55-grain FMJ bullet in a brass 5.56 case. M193 is built to the military ball spec. White Box is Winchester’s commercial 5.56 load. Listed velocities are close, and most shooters won’t see a difference at normal range distances.
What is green tip 556?
Green tip 5.56 is M855 or SS109-style ammo. It uses a 62-grain bullet with a small steel penetrator inside the jacket, and the tip is painted green to mark it. Many indoor ranges ban it, and it can damage steel targets.
Can 556 shoot 223 ammo?
Yes. A rifle chambered in 5.56 NATO can safely fire 223 Remington. The reverse is the concern: 5.56 ammo in a 223-only chamber can raise pressure. Rifles marked 223 Wylde handle both. Always check the stamp on your barrel and your rifle maker’s manual.
Is Winchester Defender 5.56 good for home defense?
Winchester Defender uses a 64-grain bonded jacketed hollow point designed to expand and hold together. Many owners pick it for a home-defense rifle. Your barrel length and setting matter, and laws on defense ammo vary, so check your state and local rules.
