best .223/5.56 ammo for 20 inch 1/9" twist barrel

[collateral]

I will be purchasing a DPMS Southpaw Panther within the next week or two.
I generally like getting the most for my money when I purchase anything, ammunition included.
I want rounds that will perform very well in several areas. Fragmenting, accuracy, and penetration.

I know that .223s arent as good at penetrating cover or obstacles as the 30 cal family is, but I'm not so much talking about penetrating either of those. I want to know that should I ever have to face an enemy with (hard/soft) body armor, I will have ammunition that won't fail me.

The barrel I will be shooting out of is 20", has an A2 flash hider, 4140 Chrome-moly steel, 6 grooves, right-hand 1x9" twist, and is button rifled.

Basically, what bullet would let me produce the highest muzzle velocity and energy out of this barrel?

Thank you very much for your time and opinions.

 

[RockyMtnTactical]

I'm partial to 55gr ammo in my 1/9's, although I will shoot 62gr and 68gr ammo as well.

 

[rbernie]

Penetration and fragmentation/expansion are somewhat opposing behaviors, and the behavior of a round in terms of either varies as the distance of the target from the muzzle changes.

In general, I'm partial to 55gr M193 stuff for most uses since I favor fragmentation as a behavior moreso than I worry about having to penetrate body armor. Bear in mind that any rifle round will likely defeat soft armor (e.g. IIIa and below). Having said that, my 1:9" twist barrels will all shoot the Hornady 75gr OTM well, and I have a bunch of that loaded up and in mags - just to have a choice.

 

[Holtzman]

"Best" round

There is no magic bullet, I like 55 grn because it was cheaper, but now anything costs an arm and a leg. You might want to try the 5.56-17N-T at The Hunting Shack. Mine was well made, new brass and shoots well, though the 223-17N-T is supposed to be slightly more accurate. My order took a couple of weeks while the made a batch, though.

The Hornady 75 grn bullet is supposed to shoot well through all 1:9 guns, and is supposed to perform well in gelatin, while giving almost .308 trajectory.

With the price of ammo right now, I think that Hunting Shack and Black Hills are the best deals on quality ammo right now.

 

[DMK]

Having said that, my 1:9" twist barrels will all shoot the Hornady 75gr OTM well, and I have a bunch of that loaded up and in mags - just to have a choice.

It works well in my Bushmaster and RRA 1/9 barrels also. I keep Black Hills 75gr. loaded in a few mags for HD.

I wouldn't worry too much about body armor with anything over 55gr.