The AR15.Com Ammo Oracle

History and Basic Design of .223 and 5.56 Ammunition.

Performance of .223 and 5.56 Ammunition.

Terminal Performance of .223 and 5.56 Ammunition.

.223 and 5.56 Ammunition Testing

Selection of .223 and 5.56 Ammunition.

Ammunition recommendations from the authors of the AR15.com Ammo-Oracle.

Purchase and Storage of .223 and 5.56 Ammunition.

Legal questions.

Miscellaneous .223, 5.56 and Other Ammunition Questions.

Ammo Oracle

Q. OK, that's complex. Simple question: Can I fire M193 ammo in my 1:7 or 1:9 twist barrel?

Yes.

M193 is essentially a "universal" round; able to be stabilized by barrels with twists between 1:14 and 1:7. Point of impact will change slightly compared to an M855 zero, so rezeroing is recommended.

Fact: The Scoop from the Army's Ammunition Information Notice (61-01) "INTERCHANGEABILITY OF 5.56MM BALL, TRACER AND BLANK AMMUNITION."


It is acceptable to use M193 and M196 ammunition in training in M16A2, M16A3 rifles and M4 and M4A1 carbines (16 percent range reduction). Substituting between types of ammunition during firing is not recommended.