Almost every ammunition mix-up starts with two names that look alike. These are the eight we see most, in rough order of how much trouble they can cause.

1. Treating .223 and 5.56 as the same thing

They share a bullet diameter and a case length, but the 5.56x45mm is loaded to higher pressure and rifles chambered for it often have a longer throat. A rifle marked 5.56 NATO accepts both. One marked only .223 Remington should be fed .223 loads. Pattern names like M193 and M855 describe military specifications for the 5.56. The M855 green-tip load, at m855 green tip 5.56x45 ammo, is loaded to NATO pressure, so check the chamber first. The M193 pattern, at m193 ammo for sale, is the traditional practice round, but the same marking check applies.

2. Putting a 5.45x39 in a 5.56 rifle

The 5.45x39 looks like a small 5.56 but is a different cartridge, with a shorter case, a .221-inch bullet and its own chambers. It belongs only in rifles built for it, and nothing about the heavier loads, such as the 65-grain FMJ at 5.45x39 65 grain ammo, changes that.

3. Assuming every hollow point expands

In a match bullet the hole in the nose is a by-product of how the jacket is formed, and its job is accuracy. The 5.56 hollow-point range, at 5.56 hollow point ammo, can include both match and varmint designs, so read the bullet description, not just the words hollow point.

4. Buying subsonic for the wrong rifle

Subsonic .308 is made for suppressed rifles. Sellier & Bellot, a Czech maker founded in 1825, loads a 200-grain subsonic round, and loads like it, at sellier & bellot subsonic 308 ammo, can fail to cycle a gas-operated action without a suppressor or gas adjustments. They also arc steeply compared with ordinary supersonic loads.

5. Using frangible where you needed ball

Frangible bullets, such as those SinterFire makes, are designed to break up on contact. They suit steel targets and training ranges. They are not for hunting or for any job that needs penetration, and the .223 versions are at sinterfire frangible 223 ammo.

6. Mixing up .308 Winchester and 7.62x51mm

Commercial .308 Winchester loads, such as Remington's 150-grain loads at remington 308 150 grain ammo, are the match for a sporting rifle marked .308 Win. Military 7.62x51mm ammunition follows its own specification, so read the rifle's marking before mixing the two.

7. Forgetting lead-free rules

Some jurisdictions require non-lead ammunition for hunting. All-copper bullets, such as Barnes makes, are the usual answer, and its .308 loads are at barnes 308 ammunition. Other makers' .308 loads, such as Hornady's at hornady 308 ammo for sale, use a mix of bullet materials, so read the bullet description before you choose.

8. Confusing the .405 Winchester with the .45-70

The .405 Winchester uses a .412-inch bullet, not the .458 of the .45-70, and it was designed in 1904 for the Model 1895 lever-action. They are different cartridges and are not interchangeable. The .405 loads are at 405 winchester ammo.

General guidance only. Never fire a cartridge in a rifle that is not marked for it, and confirm the chambering, current stock and any state shipping restrictions before ordering.