M&P15 223 or 5.56

[Michael J]

I just got this gun just wondering what ammo to use 223 or 5.56? I just found this site and thought i would ask here?
I always though that if the gun has 5.56 on the barel that is what was the best to use.
Thanks for the help.
Michael

 

[s&wchad]

Welcome to the forum.

SAAMI considers it unsafe to fire 5.56 military ammunition in chambers designed for commercial .223 Remington ammo. Different chamber specs and tolerances can create high pressures. Commercial .223 ammo in a 5.56 chamber is no problem.

http://www.saami.org/specifications...1-Unsafe_Arms_and_Ammunition_Combinations.pdf

 

[Michael J]

The gun has 5.56 on the barel so it must be the chamber for it right,
I was just wondering if one shot better than the other?

 

[s&wchad]

The gun has 5.56 on the barel so it must be the chamber for it right...

Correct.

I was just wondering if one shot better than the other?

Shoot it and find out! I believe the M&P 15 has a 1 in 9 twist, so heavier bullets (62gr+) should do better at longer ranges. You may not notice much difference at 100 yds.

 

[Michael J]

Thank you for the reply.