Back on the Chrony - 12/11/2014

With the results of the last powder charge test for this Savage 308 Winchester, I loaded up 30 rounds of 43 grain Varget powder with the Sierra 175 grain BTHP tips and headed to the range. I set up the chronograph and was surprised to see that my average muzzle velocity was still right around 2757 fps after shooting a 10 shot string.  The chrony reset before saving the results for further review, so I have to work from memory.  My extreme spread was about 36 fps, so I wasn't too happy with that, but the overall group wasn't terrible for this rifle.  Three of five were extremely close with one flier that brought the overall package to just about 1 MOA.  The three tight shots were .5 MOA or better.

Data for this load with a 10 shot group:

Avg - 2753 fps
Min - 2746 fps
Max - 2782 fsp
Ex Spread - 36 FPS
St. DEV - 12 fps

I was surprised that 43 grains pushed the 175 grain tips so fast because I got 2751 fps average out of 45 grains of Varget with 175 grain tips in this barrel 3.5 years ago.  Very interesting result to say the least.

A 5 shot group with 1 flier bringing the group to 1 inch.

Since I had a little extra time on my hands (an unusual thing), I walked my target over to the 1000 yard spot and set up a stick-on target on a closet door someone had over there.  It took about 11 minutes to walk the 1000 yards through the sage brush.  After getting the target ready and another 11 minute walk, I was back at the shooting position nearly 30 minutes later!

I used 90 clicks of elevation on the Vortex Razor HD scope and sent a few shots down range.  Although I was able to maintain the sight picture better than usual, I wasn't picking up any real slash in the dirt to identify my impacts. I assumed I was making good hits and the splash was being obscured by the door.  After 10 shots, I drove over to check it out.  Sadly, the 43 grain powder load didn't seem to have quite the elevation sustaining power as the 45 grains I've been shooting, so all my shots were about 18-20 inches low from what I could tell. It was hard to positivity identify my shot in the well shot up door.  Many of my shots got pushed off to the right of the door and with the ground being moist, there wasn't much dust being kicked up.

One of the cases had a hard time ejecting from the action even with the lower powder load of 43 grains.  Some of the cases seemed to be getting around the 2.015 length, so I've spent some time trimming them down to around 2.004-2.005 to see if that helps on the next round.