1/2x28 vs 5/8x24 for 16 inch 5.56

ModestMarksman

10 MOA shooter with a 1/2 MOA gun
Minuteman
Aug 6, 2023
21
8
New Braunfels
Building a 16 inch precision 5.56 and when asking for advice many people mentioned I should go 5/8x24 instead of 1/2x28.

The intent is to run a can like 90% of the time and I was going to run either the OCM5 or RC2 but am open to suggestions.

The main reason I’m considering the RC2 is its overall length, good flash reduction, QD and durability.

Would you go 5/8x24 over 1/2x28 on a 5.56 gun and if so what can would you run?
 
5/8-24 leaves much more meat around the bore which is always a good thing. 1/2-28 can be susceptible to torquing down muzzle devices and causing accuracy issues. I’ll always go 5/8 when I have the choice.
 
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Shop for muzzle devices in each pitch and you will answer your own question.

Since you are planning to run with a can you're doing it backwards. Select the can and muzzle device and choose the thread pitch to match.
 
Shop for muzzle devices in each pitch and you will answer your own question.

Since you are planning to run with a can you're doing it backwards. Select the can and muzzle device and choose the thread pitch to match.

For sure that’s why initially I was going 1/2x28. I just wanted to pick y’all’s brains before I drop $700 or so on a barrel since a lot of guys here really know their precision guns.
 
For sure that’s why initially I was going 1/2x28. I just wanted to pick y’all’s brains before I drop $700 or so on a barrel since a lot of guys here really know their precision guns.
5/8 x 24 for 556 options are extremely limited, which is why I said to shop for the muzzle device and/or can first.

They are out there and it may be that your can / muzzle device combo supports it.......Very generally speaking 1/2x28 is 556 and 5/8x24 is 762. OBVIOUSLY there are exceptions and that doesn't even address the metric side / options that also exist.
 
The theory behind a larger diameter muzzle is sound, and it certainly cant hurt in the accuracy department. I've looked and been unable to find documented testing though. I wouldn't lose sleep either way, pick your muzzle device and thread accordingly.
 
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My new SPR has a 5/8x24 muzzle thread. I initially wanted to run my SOCOM mini on it. But that's a no go. Surefire does not make a 5/8x24 device that their 556 can will fit on.