Hopefully everyone is still reading this, as I got busy for a few days and didn't have time to finish up this article (One more post after this one, I promise!). Either way here's another installment.
Gathering Data - Time to hit the range!
So here is the fun, and yet at times tedious part of this processes. Aside from interpreting data (the next section) this is where you're most likely to go wrong, so attention to detail is critically important in this phase.
If you're getting ready to go to the range to test out some new loads, here's a quick checklist:
* The gun
* The ammo
* Calibrated targets or Overlays
* Chronograph (DON'T FORGET SPARE BATTERIES!!!!!)
- All of the other bits and bobs that go to the chrono, make sure you have a tripod to put it on, some sandbags to weigh it down with so it doesn't blow over, wires, spare wires, extra sky screens etc.
* Pad and paper
* Something to write with
If you are on your way to the range and you forgot any of these things, you may as well turn around and go home now, otherwise you will not collect any useful data.
Hopefully you remembered everything, bought it on the way, or were lucky enough to borrow something you forgot when you arrived. So lets go over some basics of equipment set up.
Set up your calibrated targets at a designated range (and the range for which they are calibrated for), now hopefully you have long line-breaks, as you will now need to set up the skyscreen assembly for your chronograph. Having a friend here can help quite a bit.
Place your skyscreens from 5-20' from the bench, 5' is ok for pistols, 20' is better for rifles, otherwise the muzzle blast can disassemble your sky screens just as easily as a bullet strike will. Once you have the distance right, having a friend who can stand behind your bench, directing you to move left-right-up-down, angle up or angle down and line up the skyscreen is definitely worth buying them lunch for showing up. In a pinch, most of the other people at the range will also be happy to help you with this operation, however, sometimes their skill at direction is greatly lacking.
Once you have access to your bench (line's now hot!), you should first fire some known ammo through the chronograph to make sure it's measuring properly. Measurements that are outside the norm, measurements that are missed, or measurements taken when you are not shooting can be an indication of bad placement of the chronograph, or of environmental interference (wind and florescent lights are the two biggest offenders except perhaps for no lights).
After testing your equipment the fun stuff begins. Make notes of which load you are testing, you can number them, or simply write down the details of each cartridge. i.e. Load 1 or 24.3grs varget...
When you fire the first round in a string, be sure to catch the first fired round, inspect the case, look at the primer, and look for signs of high pressure, if any is found you may not want to shoot the rest of the string, or shoot loads of more powder. Keep notes of any signs you see on the cartridge case, whether there are signs of high (even if not excessive pressure), also make notes about the ambient conditions, most cartridges will generate higher pressures with hotter ambient temperatures.
At the end of each fired string, switch to using a different bullseye on the target, and measure group size wither with overlays, or using calibrated targets. Make notes of which loads have a smaller group size.
As I said earlier, load development can be a very time consuming process, and is easier to perform with a test range at hand, this makes gathering data much faster, requires loading fewer rounds, and there is no waiting for line breaks.
By now, you should hopefully have taken some good data. The next article is going to be all about data analysis.
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