Ammo Talk--.223 vs 5.56 and other random numbers

Ammo Talk--.223 vs 5.56 and other random numbers


Welcome back to the 5th installment of my blog, in which I don’t claim to be an expert, in fact the very opposite. I’m a new user to the AR platform and want to share my findings and experiences as I go through and build rifles as well as being the Operations Manager at Tyrant Designs.


The .223 Remington and the 5.56mm NATO are the most commonly chambered rounds associated with the AR platform. Today I will discuss both and which you should use.


I’ve found a lot of conflicting information regarding shooting .223 and 5.56 out of your AR 15. Can you shoot both? Do you have to pick one or the other? Aren’t they very similar, what are their differences? How do I know which is right for my rifle? These are all good questions I’ll address in this post, so you can shoot the ammo that is right for your rifle. The simplest way to check is to load both at the same time and whichever comes out first wins, gladiator style?



THAT WAS A JOKE. Please please please don’t do that and try and sue us, we have lawyers!


The .223 Remington and the 5.56x45mm NATO have the same external dimensions but the pressures of each can be different. In short, the 5.56mm is a higher pressure load and CAN NOT be shot in a barrel meant for .223. Because of the lower pressure of the .223 , it can usually be shot in a barrel meant for higher pressure loads like the 5.56.


The .223 Remington is designed to be shot through a chamber that has a shorter leade, or distance between the mouth of the cartridge and where the rifle touches the bullet. The 5.56 needs a longer leade. Manufactures have actually addressed this by designing rifles that can shoot both cartridges safely. Do not assume you can shoot both just because .223/5.56 is inscribed on your barrel. Consult your owner’s manual and find out what your rifle is designed to shoot.


If you’ve made it this far then I like you. Thanks for tuning in and happy shooting!

1 Response

Cesar Aquino
Cesar Aquino

February 10, 2017

That’s hilarious!! Don’t sue us, we have lawyers. Great info. Better to be safe then sorry.

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