View Single Post
Old 04-07-2014, 05:49 PM   #10 (permalink)
Whiskey Hammer
Shaped Ammo Advocate
 
Whiskey Hammer's Avatar
 
Join Date: Nov 2013
Location: Jacksonville, FL (and a lot of the time, Tampa)

And... heres the rough cut of the data. Be sure to look at the below before you dive in.

In the first round, my process with the variables was to create a baseline using a speculative "most accurate" combination of factors and then test each factor one at a time, while the others remain constant with the baseline. In the second round, I wanted the test to be more "apples to apples" with the Punkworks test so that the two sets could be readily compared or used together. Hence the difference in variable schema between the first and second round.

The chrono in the first few groupings of the second test was malfunctioning due to a dying battery. Those cells have been highlighted in a darker orange. The battery was replaced, and the reading became more reasonable and consistent with previous testing.

The rigid variable test group in the second test suffered from a shifting POA every four shots due to operator error. The groups are seperated by dashed lines. I might artificaily center them later (or let someone with excel skills take care of it). Edit: I ran the numbers and unsurprisingly the more groups you break a population into, the more exaggerated the corrective effect of the mathematical centering.

Some quick notes on the variable terminology:
  • Rigid vs Free-Float: whether or not the barrel was braced against the edge of the firing bench/clamp to pretension the barrel and prevent flexing.
  • Unsorted/Ratioed vs Sorted: whether or not the ammo lot was sorted to size. If the ammo was unsorted it was still made to reflect the size ratios found in the Manufacturing Consistency phase of the test.
  • Untapped vs Tapped: whether or not an attempt was made to settle the paint into the nose of the round by a forcefull tapping.
  • Tipless vs Tip: whether or not the barrel had the factory tip during firing.

Last edited by Whiskey Hammer; 09-23-2014 at 02:17 PM.
Whiskey Hammer is offline   Reply With Quote