Barrel Length 12.5″ Caliber 5.56 NATO

[Robert Mitchum]

Best choices for Defensive ammo : Barrel Length 12.5″ Caliber 5.56 NATO
Rifling 6 RH Grooves 1:8 Twist.

Use would be for Home & Traveling in a vehicle.

I have ammo for my 16" Barrel AR.
Getting a 12.5" Barrel so not sure which is the way to go.
Have a good stash of the Ammo listed below .. Not sure which is the better choice.

TAP 55 gr GMX BARRIER
Speer Gold Dot LE Duty 223 Remington Ammo 55 Grain Soft Point
223 REM 62GR SPEER DUTY RIFLE GOLD DOT SOFT POINT (24445SP)
Speer Gold Dot LE Duty 223 Remington Ammo 75 Grain Soft Point
223 REM 62GR FEDERAL TACTICAL BONDED (LE223T3)
223 REM 55GR FEDERAL TACTICAL BONDED, (LE223T1)
Winchester 5.56mm 77 gr Hollow Point Boat Tail Ranger RA556M BX
Winchester 223 Rem 64 gr Ranger Power-Point RA223R2 BX
Winchester 223 Rem Match 69 gr Ranger Boat-Tail Match RA223M BX
Winchester 5.56mm 64 gr Ranger Bonded Solid Base RA556B BX

[TGS]

The velocity difference between 12.5" and 16" is pretty minimal, a little over 100fps, so unless you're looking stack 'yotes at 300 yards then whatever floats your boat; any of the recommended SD/duty loads will be fine.

[WDR]

Out of a shorter barrel, I'd tend to pick the lighter 55-64gr bonded bullets, over the 75 grain versions, just to keep the velocity up a smidge, and maybe get a litter wider expansion "window" vs the heavier weights. The opposite is true with OTM type loads (69/77 SMK, 68/75 BTHP etc)... I'd select the heavier bullet in that case, since the lighter bullets sometimes are a tad short on penetration. I settled on the 62/64gr Gold Dot or Fusion loads a while back.

In any case, I'd pick one of the bonded bullet loads over a OTM for general use. I wouldn't lose a lot of sleep if all I could get was OTM though.

[fatdog]

For all my SBR's 12.5, 11.5, 10.5 I went with the 55gr Gold Dot because it is (in normal times) usually the lowest cost of those choices allowing me to stack it deeper, and I found the whole zero and POA/POI thing to be a bit closer to 55gr practice ammo than the 62/64/75/77 stuff.

I also buy into the idea of getting as much velocity as I can out of a defensive round in the SBR set of uppers I have. I am thinking any of those recommended rounds work in the 12.5, but I was able to stack my pile of the 55gr gold dots a lot higher prior to this outage.

[littlejerry]

There is a fantastic post over on Arfcom with velocity data from 10.5, 11.5, 12.5, and 14.5 barrels for common defensive ammo. The velocity loss for each load is definitely not the same.

[Sensei]

My vote is the Winchester RA556B. I’ve had great luck from it out of various SBRs

https://pistol-forum.com/archive/index.php/t-26978.html

It produces roughly 2500 fps from a 10.5” barrel.

[S Jenks]

I believe the 5.56 Hornady 55 grain GMX TAP Barrier has been discontinued. If you have a supply of it, rock on.

[Robert Mitchum]

My vote is the Winchester RA556B. I’ve had great luck from it out of various SBRs

https://pistol-forum.com/archive/index.php/t-26978.html

It produces roughly 2500 fps from a 10.5” barrel.

Sounds good to me .. Thanks !

[littlejerry]

Here is the post on Arfcom:

https://www.ar15.com/forums/ar-15/Su...4088/#i7456813

In particular the Fusion MSR is substantially faster than the corresponding Gold Dot load. The 12.5 velocity seems to be close to what a 16" rifle would chrono.

The Barnes VorTX loads are also smoking fast, so much so that it really negates any advantage of a longer barrel.

[5pins]

Hornady makes a 75gr TAP SBR load that looks interesting. I have never tried it so I can't give any personal experience.

https://www.hornadyle.com/rifle-ammu...-gr-tap-sbr#!/