Picture two boxes side by side: a case of M193 and a box of bonded hollow points. Some gel clips make them look alike up close. So why pay more for the hollow points? It’s a fair question, and the answer is in how you read 5.56 ballistic gel results. Military ball ammo and purpose-built expanding loads can look alike in one test and very different in the next.
This guide explains how 5.56 NATO bullets act in gel, why distance and barrel length change so much, and how the 5.56 loads at Bulk Ammo Vault compare. We haven’t run our own gel tests. We don’t print depth or expansion numbers for any specific load. All velocity and energy figures come from our catalog.
Two Kinds of 5.56: Ball and Expanding
Military ball
M193 and M855 are full metal jacket rounds. They aren’t designed to expand. M193 uses a 55-grain lead-core bullet. M855 uses a 62-grain bullet with a steel penetrator. Both were designed for military rifles, not for controlled expansion.
Expanding loads
Bonded hollow points, tipped bullets and copper bullets are designed to open in a set way. They aim for steady results across a range of speeds. That’s the main thing you pay for.
How to Read a 5.56 Gel Test
Start with the setup. A fair test uses calibrated 10% ordnance gelatin, chilled and checked with a steel BB. Then look at three results: penetration, expansion and retained weight.
The FBI protocol, built for handgun duty ammo, looks for 12 to 18 inches of penetration. Many 5.56 testers compare against it too.
Ball ammo: watch for yaw and breakup
FMJ 5.56 bullets often travel straight for a short distance, then turn sideways. At high speed, some designs may also break at the cannelure. When that happens close to the muzzle, a gel block can look dramatic. As the bullet slows, from range or a short barrel, it may simply yaw without breaking up. That’s why ball ammo results vary so much.
Expanding ammo: watch the recovered bullet
For bonded and copper bullets, the recovered bullet tells the story. Look for a clean mushroom or even petals, and high retained weight. Steady results across several shots matter more than one great-looking block.
5.56 Loads We Carry, Side by Side
| Load | Bullet | Grain | Velocity | Energy | Pack |
|---|---|---|---|---|---|
| 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) |
| IMI 556 M193 55 Grain FMJ | Full Metal Jacket | 55 | 3,215 fps | 1,262 ft-lbs | 1,200-round case (40 x 30) |
| 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) |
| IMI M855 SS109 5.56 62 Grain FMJ | SS109 Penetrator Full Metal Jacket | 62 | 3,020 fps | 1,256 ft-lbs | 1,200-round case (40 x 30) |
| Winchester Defender 5.56 64 Grain Bonded JHP | Bonded Jacketed Hollow Point | 64 | 2,800 fps | 1,115 ft-lbs | 20-round box |
| Black Hills 5.56 62gr TSX Lead-Free | Barnes Triple-Shock X solid hollow point | 62 | 3,000 fps | 1,239 ft-lbs | 50-round box |
| Hornady Superformance 5.56 55 Grain CX Lead-Free | Solid Hollow Point (Hornady CX) | 55 | 3,175 fps | 1,231 ft-lbs | 20-round box |
| Winchester Match 5.56 77 Grain Sierra MatchKing | Sierra MatchKing Hollow Point Boat Tail | 77 | 2,750 fps | 1,293 ft-lbs | 20-round box |
The Winchester M193 lists 3,180 fps and 1,235 ft-lbs. The Winchester M855 Green Tip lists 3,060 fps and 1,289 ft-lbs. On the expanding side, the Winchester Defender 64 Grain Bonded JHP lists 2,800 fps and 1,115 ft-lbs, and the Black Hills 62 Grain TSX lists 3,000 fps and 1,239 ft-lbs.
Notice that the expanding loads list lower speed than M193. Heavier bullets start slower. They count on design, not raw speed, to do their work.
Barrel Length: The Big Variable
Factory velocity is often measured from a long test barrel. Real 5.56 rifles range from short-barrel builds to 20-inch rifles. Every inch you cut costs some speed.
Why does that matter in gel? Ball ammo leans on speed to yaw hard or break up. Lose speed, and the dramatic results fade. Bonded and copper bullets are less sensitive, though they still need a minimum speed to open. If you run a short barrel, favor a load built for it, and read gel tests fired from a similar length.
Barriers and Clothing
The FBI set includes heavy clothing, wallboard, plywood, sheet steel and auto glass. Each one is tough on a light, fast bullet.
- Clothing can clog hollow points. Tipped and bonded designs help.
- Auto glass can break up light bullets early. Bonded and copper bullets tend to hold together better.
- Wallboard matters for home defense. Any 5.56 round can pass through interior walls. Know your backstop.
Match and Specialty 5.56
The Winchester Match 77 Grain Sierra MatchKing lists 2,750 fps. It’s a match load built for accuracy. Open-tip match bullets can act very differently in gel from one test to the next. Read those results with care and use match ammo for what it’s built for: precision.
The Hornady Superformance 5.56 CX is a copper hunting load at 3,175 fps. It’s a good reference point for lead-free performance.
So, Ball or Expanding?
- Training and practice: M193 or M855 is fine, and it’s cheaper by the case.
- Home defense: an expanding load like the Defender gives more steady results across distances and barrel lengths.
- Hunting: an expanding or copper hunting bullet. FMJ is banned for big game in many states.
Laws on self-defense, hollow points and hunting vary. Check your state and local rules. For more, see our M193 ammo guide and the 223 ballistic gel guide.
Shop 5.56 Ammo
Browse all 5.56 ammo, from bulk ball to premium defense and hunting loads. Read 5.56 ballistic gel tests with barrel length and distance in mind, then pick the load that fits your job.
Frequently Asked Questions
Do M193 and M855 expand in gel?
No. Both are full metal jacket rounds and are not designed to expand. They may yaw, and at high speed some may break up, which can look dramatic in gel. As speed drops with distance or a short barrel, those effects fade. Expanding loads give steadier results.
Is 5.56 good for home defense?
Many people choose a 5.56 rifle for home defense because it is light and easy to shoot well. Pick a load designed to expand, such as a bonded hollow point, and know that any 5.56 round can pass through interior walls. Check your state and local laws.
Does barrel length affect 5.56 performance?
Yes. Shorter barrels give lower velocity. Ball ammo depends on speed to yaw hard or fragment, so short barrels reduce those effects. Bonded and copper bullets are less sensitive but still need minimum speed. Compare gel tests fired from barrels like yours.
Is 300 blackout bigger than 556?
The 300 Blackout fires a .30 caliber bullet, which is wider and usually heavier than the .224 inch 5.56 bullet. The 5.56 runs faster and shoots flatter. Both fit AR-15 rifles with the right barrel, but the rounds are not interchangeable.
