Load development data, thoughts/opinions?

[thisguy65]

I did another one today, per say. I jumped around randomly choosing the cartridge and waiting 2 mins between shots. Barrel wasn't even really warm when I check it, so 2min is over kill.

Then I went all nerd and graphed the velocities that I recorded over a magnetospeed as well as the ES/SD. Steve at 6.5guys is the one I got the excel sheet/idea from. I downloaded his and put my information in, so prop goes to him. It honestly makes things alot easier to see for sure. 42.1 and 42.3 has a wide note it appears. However my velocity is not where I want it to be at. Then at 42.7 and 43.1 show low ES/SD as well how ever they are not in a wide node. My concern is temperature effecting the rounds so that they shoot (have high SD/ES) like the charge weights on each side of them. Basically if it got down to 40 degrees, the temperature would effectively lower my charge weight from 42.7 to 42.5. However it's just a theory, only one way to test the idea.

Since the barrel is still new, I'll load up 42.1 42.2 and 42.3 in 10 rounds and shoot those to see how the SD/ES are. Whatever the winners is of that one, load up 5 rounds at different seating depths.

The two charge weights that got chopped off at 42.9 (top) and 41.9 (bottom)

 

[BountyHunter]

I would shoot 42.6 and 42.7 while you are at it.

 

[thisguy65]

I would shoot 42.6 and 42.7 while you are at it.

Why is that exactly? There looks to be a higher SD/ES than the other. Graph wise 42.6 would fall on steeper section of the graph compare to the 42.2 that is more flatter?

Not saying you are wrong, just want to understand why you said to try 42.6 and 42.7

 

[BUSTINDOGS]

What powder bullet combo are you using?
With those results a I would load them at 43.2 and have some fun.

 

[thisguy65]

H4350

6.5 creedmoor 140hybrids.

 

[dsculley]

Wash this shot at 100 yds? Is the diamond in the center 1"? If the charges had been laid out in numerical order the target would be a bit easier to read. The group centers for 42.5, 42.7 & what i assume to be 42.9 are essentially in the same spot. As was stated earlier, I would definitely try around 42.7. Did you test seating depth yet?

You seem to be putting a lot of weight on the graph, which may or may not be representative of actual performance. I assume it is one of the linear regression graphs available in Excel that smooths the data. While it is a good tool, I would put more weight on the target.

If you are worried about POI change with temp change, then I would re-shoot at the temps I expect to encounter to check for temp sensitivity.

FWIW,

Dennis

 

[thisguy65]

Wash this shot at 100 yds? Is the diamond in the center 1"? If the charges had been laid out in numerical order the target would be a bit easier to read. The group centers for 42.5, 42.7 & what i assume to be 42.9 are essentially in the same spot. As was stated earlier, I would definitely try around 42.7. Did you test seating depth yet?

You seem to be putting a lot of weight on the graph, which may or may not be representative of actual performance. I assume it is one of the linear regression graphs available in Excel that smooths the data. While it is a good tool, I would put more weight on the target.

If you are worried about POI change with temp change, then I would re-shoot at the temps I expect to encounter to check for temp sensitivity.

FWIW,

Dennis

Yes, it was shot at 100 yards. the Diamonds are 0.5" I have not done a seating depth test yet. This was test to see what gave me low SD/ES. Fine that charge weight.. Then move to seating test to tighten up the group.