In 2010, I posted a sneak preview of Hornady’s 75 gain 5.56mm Superformance ammunition. When chronographed from a 20” Colt M16A2 barrel, this Superformance load produced the highest muzzle velocity for a 75 grain load that I had ever seen; 2909 FPS. The table below shows the muzzle velocity of the Superformance load compared to other Hornady loads charged with standard powders.
Unfortunately, this increased velocity load came with a price; and I’m not referring to dollar signs. The accuracy of the 5.56mm 75 grain Superformance load was . . . how shall I say this? . . . sub-standard . . . for what myself and others had come to expect from a “premium” heavy OTM factory load. The smallest 10-shot group that I obtained from a chrome-lined, NATO chambered, 20” Colt HBAR at a distance of 100 yards had an extreme spread of 3.4” and a mean radius of 1.16”. Others who tested the load using match grade stainless steel barrels fared hardly better.
Since that time, Hornady has made a few changes to the 5.56mm 75 grain Superformance load. For starters (and of no real consequence) the boxes for this load now carry a “match ammunition” nomenclature instead of the original “Varmint” label. Secondly, this load is now seated with the 75 grain “T2” projectile instead of the T1 found in the original load.
Thirdly, the velocity of this 5.56mm Superformance load has been reduced. While the original load produced of muzzle velocity of 2909 FPS from a 20” barrel, the new version had a muzzle velocity of 2863 FPS for a difference of 46 FPS. Most importantly, this new version of the load has shown significantly improved accuracy over the original version.
Following my usual protocol for accuracy testing, (described in detail here) I fired three 10-shot groups in a row from a distance of 100 yards from a Lothar Walther barreled semi-automatic AR-15 with the Hornady 75 grain 5.56mm Superformance “Mod 1” ammunition. The resulting 10-shot groups had extreme spreads of:
1.31”
1.93”
1.02”
for an average 10-shot group extreme spread of 1.42”. The mean radius for the 30-shot composite group was 0.48”.
The smallest 10-shot group of the “Mod 1” Superformance ammunition.
It should be noted that the Superformance powder creates a higher port-pressure for less than full-length gas systems compared to standard powders.
I just recently fired some of this through a Rainier 18" Ultramatch SPR barrel and every primer was popped. It’s definitely some hot stuff. I wasn’t shooting for groups so I can’t speak on the performance.
I apologize, I fired the 75 grain 223 superformance. For some reason I have a box of 5.56 and .223, and I fired the .223 first. The velocities, per the label, are higher for the .223.
Anyway, here’s what I got. Sorry if the images don’t come out clear.
Absolutely. Wylde chambers are horrible with hot ammo. None the less… if a load won’t fire safely in a Wylde, I don’t want to mess with it. We’re able to reach way beyond practical/functional range of 77 OTMs without the downsides of super hot loads.
The velocities that this and the BH load are getting are impressive. But in my opinion, with the 77, you don’t really have to push them that fast…
The velocity of the 223 Remington load is obtained from a 24" barrel with a SAAMI chamber, while the velocity of the 5.56mm load is obtained from a 20" barrel with a NATO chamber.
