Bitterroot Bugle post categories

Global Skywatch

ammo load testing

target wallI meticulously assembled 7 groups of loads with 165-grain Hornady SST bullets. The hand-weighed charges ran from 5 with 43.4 grains of Varget powder to 5 with 44.0 grains, every group of five separated by tenth-of-a-grain increments.

I also loaded up and tested 7 groups of 168-grain Sierra HPBT match bullets. These were pushed out by 42.7 to 43.3 grains of Varget, also groups of five in tenth-of-a-grain increments.

My shooting was all done at 200 yards from a bench rest through the Leopold scope my .308-caliber AR-10 always wears. The wind was kind to me, not disturbing us at all. The targets were some 50-foot rapid-fire pistol targets I had a lot of. While not ideal for load testing, they gave a nice aiming point and worked fine.targets of Hornady SST

A lot of reloaders cast rather than weight each charge, saying “A few more or less flakes of powder won’t matter.” Look at those groups. The difference isn’t just a few more or less in each one of the five shots, they are exactly the same with a mere tenth of a grain separating each group. It makes THAT much difference.

The Hornady SSTs are popular hunting bullets renowned for their accuracy and prized for their controlled expansion on target. I’m always a bit let down with my .308 when I compare it to my .223 accuracy. That is unfair. The 3″ group to the left is plenty good for its intended purpose. That’s as good as I think I’ll get with those bullets in my rifle. Good enough; not dazzling.

Interestingly, the groups one tenth of a grain on either side of the best group were significantly more widespread. That is a very narrow sweet spot. I think I will not buy more of those bullets.
targets of Sierra 168s
My rifle’s sister loves 168 grain Sierra Hollow Point Boat Tail Match (HPBT Match) bullets launched by 43.0 grains of Varget. Being essentially identical twins, I loaded up groups of 5 on either side of that – 42.7 grains to 43.3.

The first group of Sierras is the middle target in the middle row. They just got better and better, the hotter they came out. The 2″ group is a bit high and left of center, but that is simply scope adjustment. The question is hanging out there, “Will it continue to get better with another tenth or two?

Back to the loading bench. I have to know.

One thing for certain, the Sierras are more accurate in my rifle. Will they suit purposes besides punching holes in paper? That kind-of IS the point of rifle and rifleman.