What COAL for maximum reliability in a 5.56 AR?

[Franko]

What maximum OAL would you use for ammo intended for AR usage that where reliable feeding via PMAG's is top priority?

I am getting ready to start producing AR-15 ammo and don't ever want to worry about it not working. If it matters, projectiles are likely to be some combination of 77TMK, 73ELDM, 64BSB, and 62GoldDot.

Thanks in advance.

 

[simonp]

2.260 is max OAL for a pmag longer than that and you’re either having rounds stuck in the magazine or single feed.

OAL for each bullet though may differ - check your manuals.

 

[sinister]

You'd think there would be some kind of standard drawing. Hmm.

 

[Franko]

You'd think there would be some kind of standard drawing. Hmm.

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With stacking tolerances and murphy's law being what it is, I'm thinking that running at 2.260 OAL might have some risks. I'd be thrilled if I was wrong.

 

[redbullitt]

Mags make it a little muddy since they vary. For any cartridges that matter I go 2.250 to 2.255 and don't have any hangups in mags, gi, lancer, or random junk ones here.

2.260 can give hangups with any weirdness in the mag. More than 2.260 gets less and less reliable depending on what mag in my experience.

Super short can be funny too, but that won't be an issue with normal projectiles.

 

[Top O' Texas]

asc mags can get coal to 3.150ish. might not chamber, so check before loading.

 

[Old Man with Gun]

Use the COAL recommended by the maker.