Load Testing Insight: 5 “Rules” for Load Work-Up

Don’t waste time and money collecting half-boxes of “loser loads.” Here’s how to start and finish load work-up in one day.


Glen Zediker


Last time I talked a little about keeping your ammo pressure-safe, under a range of conditions. Quite a bit of that dealt with observations made during load work-up. So this time I’d like to talk more about the work-up process I use.

The reason for the term “work-up a load” is pretty clear: we’re almost always looking to get the highest velocity we can, safely. High velocity, or, more clear, higher velocity, is usually all good. Shorter time of bullet flight to the target means less drop and drift, and a harder impact.

So working up means increasing propellant charge incrementally until we’re happy. Happy with the velocity or happy that the cases are still able to hold water. Ha. As said last time, it’s vitally and critically important to have a stopping place, a goal to be reached, prior to testing.

I also mentioned an “incremental” load work-up method that I have followed for many years, and it’s served me very well. I do all my testing and work-ups at the range. I load right then and there. I take boxes of sized and primed cases, and my Harrell’s powder meter, and a small press that I c-clamp to a bench. The press, of course contains my seating die. And the most important pieces of gear are a notebook and a chronograph.

load at the range
You don’t have to invest a fortune to take your handloading show on the road. Some c-clamps and one of these little Lee Reloader presses is all you need! And a good powder meter. One with a clamp is handiest, or just mount it to a piece of wood and clamp that down (even a pickup tailgate works just fine).

Before the trip, I have taken the preparation time, done the homework, to know exactly how much “one click” is worth on my meter. It varies with the propellant, but by weighing several examples of each click-stop variation (done over at least 4 stops) I can accurately increase the charge for each test a known amount.

reloading at the range
I map out the incremental values of each click on my Harrell’s meter adjustment drum with the propellant I’ll be testing, and it’s really easy to step up each trial with confidence. I carry the whole kit in a large tackle-type box.

I work up 0.20 grains at a time. Sometimes it’s more if I’m reading a low velocity initially. Since I have a meter with a “Culver” insert, which I trust completely, I actually reference the number of clicks in my notes rather than the weights. I check after the weights when I get back home, and I do that by counting to the setting and weighing the charge. It’s easy enough also to throw a charge into a case and seal it over with masking tape.

I started loading at the range because I got tired of bringing home partial batches of loser loads. And, you guessed it, the partial boxes usually contained recipes that were too hot. The only way to salvage those is to pull the bullets. Tedious. Or they were too low, of course, and fit only for busting up dirt clods. Plus, I’m able to test different charges in the same conditions. It’s a small investment that’s a huge time-saver.

During my work-up, I fire 3 rounds per increment. As it gets closer to done, I increase that to 5. Final testing is done with 1 20-round group. Does 3-round volleys seem inadequate? It’s not if there’s confidence that the rounds are being well-directed and speed is being monitored. If I’m seeing more than 10-12 fps velocity spreads over 3 rounds, I’m not going to continue with that propellant.

Here are a few things I’ve found over the years to better ensure reliable results. Learned, of course, the hard way.

  1. Limit testing to no more than one variable. I test one propellant at a time, per trip. If you want to test more than one on one day, bring the bore cleaning kit and use it between propellant changes. Results are corrupt if you’re “mixing” residues. Same goes for bullets. Otherwise, though, don’t clean the barrel during the test. Don’t know about you, but I fire my most important rounds after 60+ rounds have gone through it, so I want a realistic evaluation of accuracy (and zero).
  1. Replace the cases back into the container in the order they were fired. This allows for accurate post-testing measurements. Use masking tape and staggered rows to identify the steps. I use 100-round ammo boxes because they have enough room to delineate the progress.

    ammo pressure
    Keep track of the cases in the order they were fired. This helps later on back in the shop when the effects can be measured. This little outing here, though, didn’t require a gage to cipher: a tad amount hot on that last little go around (last case bottom row on the right). Thing is, I didn’t load a whole boxful of those chamber bombs to take with me, and that’s the beauty of loading right at the range.
  1. Use the same target for the entire session. (Put pasters over the previous holes if you want, but don’t change paper.) This helps determine vertical consistency as you work up (when you’ve found a propellant that shows consistency over a 3-4 increment range, that’s better than good).
  1. Exploit potentials. If you take the lead to assemble a “portable” loading kit, the possibilities for other tests are wide open. Try some seating depth experiments, for instance. Such requires the use of a “micrometer” style die that has indexable and incremental settings.
  1. Go up 0.20 grains but come off 0.50 grains! Said last time but important enough to say again here. If a load EVER shows a pressure sign, even just one round, come off 0.50 grains, not 0.10 or 0.20. Believe me on this one…

Last: Keep the propellant out of the sun! I transport it in a cooler.

shooting chrony
Chronograph each round you fire. It doesn’t have to cost a fortune to get an accurate chronograph. This one is inexpensive and, my tests shooting over it and my very expensive “other” brand chronograph (literally one cradled in the other) showed zero difference in accuracy. The more expensive chronographs mostly offer more functions. The muzzle-mounted chronos are fine and dandy too.

The preceding was a specially adapted excerpt from the new book, Top-Grade Ammo by Glen Zediker. Check it out at ZedikerPublishing.com or BuyZedikerBooks.com

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