Help interpreting this ladder test

aaronk

Sergeant of the Hide
Full Member
Minuteman
Jan 21, 2018
118
98
Washington
This was a ladder test with Varget and 180g Berger Elite Hunters. First time using Berger's hybrid bullets. They were seated at mag length, which ended up being .040 off my lands. I've never seen this in a ladder test before, but I've also never loaded a bullet with as much jump as these Bergers, which is the only thing I can conclude as to why I really didn't see the velocity increase.

Where would one go from here?

Thanks!

Screen Shot 2018-12-02 at 6.59.44 PM.png
 
If that data is correct, 43.4 is your best charge

You can repeat the test to confirm with a narrower range, or just go straight to the seating depth test. Load up a bunch at 43.4 and move in .01 increments until you get the tightest grouping. I typically shoot 3 of each depth and find the cluster
 
  • Like
Reactions: JimLee
If that data is correct, 43.4 is your best charge

You can repeat the test to confirm with a narrower range, or just go straight to the seating depth test. Load up a bunch at 43.4 and move in .01 increments until you get the tightest grouping. I typically shoot 3 of each depth and find the cluster

Thanks, I should have clarified my original post - I'm looking for why I only saw a 35fps increase over 1.8 grains. I typically see a much larger spread in velocity over that charge weight range and the node really sticks out, although I agree 43.4g looks interesting.
 
Last edited:
Because these results all fall within a margin of variance. Shoot the ladder on paper at distance and you’ll find an actual answer.

Test it again using the same exact method and I doubt your results will look the same.
 
Velocities flatten over charge ranges. It’s never linear. Try shooting the test again for confirmation. I’ve never done one over a chrony; just at 5-600 yds and marked the vertical
 
Velocity will flatten over a charge range, but not multiple times. Keep in mind you are trying also to determine where you are on the pressure curve. The part you are looking for is where it is relatively flat/even climb, then a jump. You want to find the jump, where the same increment of powder gives a larger increase in velocity.

I'd also suggest more charges at the same weight.