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

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

  1. The process is an interesting approach, however I have rarely found the highest velocity load to be the most accurate. Additionally environmental effects would make apparently acceptable loads unacceptable in other environments Like the equipment choices. The portable workmate seems very handy.

  2. “If I’m seeing more than 10-12 fps velocity spreads over 3 rounds, I’m not going to continue with that propellant.”

    Wait .. what??? Did I just read this right? Are you talking about extreme spread? Like the difference between min and max? My spread is anywhere between 30 and 100 fps. One time I got 14 fps spread with Benchmark in 4 shots, I subtracted one because it looked like out of place and that was unbelievably good! The ironic part this was with copper blemished bullets I bought. I also discovered that just because you have most tight spread it doesn’t mean automatically it’s most accurate group. I have several powders I tried and several different projectiles, but best I’ve got are Nosler 40gr I bought on huge clearance. Best group I got was under 1″ at 100 yards and that was with Sierra 69gr that were part of fire lapping kit. They say not to shoot for groups, but I did and I was amazed how it came out.

    1. You don’t mention the gun you are shooting, but based on your description of powder and bullet weights, I assume you are shooting a 223 Remington or 5.56 in AR platform. If you could shoot the range of 40 gr to 69 gr, your barrel twist rate is likely 1:9, and therefore it would be an AR platform – most bolt action 223s are 1:12 twist rate and the 69 grain might be marginally stable depending on velocity. You obviously have some experience reloading since you have several powders, and a chronograph and recognized the author likely meant Standard deviations of 10-12 fps rather than Extreme spread. If you are shooting an AR platform and the best you can do (especially with the 69 gr Sierra and Benchmark powder) is “just under 1″, I suspect that it’s either your shooting ability/form, your bench set-up being unsteady or perhaps your trigger. Most ARs with a spec trigger are difficult to wring the most accuracy out of them. I have two ARs in 223/5.56 and with the Sierra 69 SMK bullet and Benchmark AND the fantastic AR-Gold aftermarket trigger have developed loads that shoot in the 1/2” realm. I see a lot of new and even experienced shooters at my ranges and when they can’t get their guns to group well, many times they are still shooting the factory spec trigger. I let them shoot their ammo in my AR and they are amazed at how much better they can shoot with a good trigger.

      1. You are correct mostly, but my gun is Mossberg MVP with 18″ barrel and 1:9 twist rate if I remember barrel length correctly. I don’t have AR, because I prefer bolt guns, because they are more comfortable to shoot scoped resting on the sled even though I got two new Giselle 2 stage triggers sitting on my desk right now that I need to get rid of ($150). I recognize the importance of good trigger, I had experience with high end triggers. The trigger on my MVP is pretty good, much better than Colt AR my cousin owns. All my bullets except Nosler are bulk type. I just don’t like spending 20 cents per bullet. The only time I shot SMKs was because they were used in fire lapping kit by David Tubb, I realize now, I would have been much better off buying my own set of abrasive powders, so I can use in multiple guns. When I was loading SMKs I was just using smallest recommended grain amount, I think I used 18gr of IMR 4198, so I wasn’t trying to develop accurate load, yet results impressed me. The benchmark powder data I mentioned wasn’t shot for accuracy, only to measure velocity. I might get 1/2″ @ 100 yards with quality projectiles and right powder, another thing to consider it’s a cheap rifle, I think I paid $460 few years ago (my first centerfire). Eventually I want to buy a better rifle with nice laminate stock possibly. Right now I am on the quest to see what can I achieve with my bulk projectiles and this is where this article taught me something I didn’t know. You see where I live it’s about 1:45 drive to the range where I can shoot all day long undisturbed and I just can’t do that very often. Local ranges are not going to let me even use Chronograph – members only! It’s $375 to get started and than it’s $175 per year, so I stick to free range, I can do whatever I want there. Ok, so what I was getting at is developing loads have been obstacle, because like author said I just end up wasting time preparing all kinds of combination of ammo, it would be good to try on the spot, but in the past I’ve discovered that digital scales and outdoors don’t play nice, so this is where his Harrell’s meter solves the problem, but the price of it!!! I don’t think I can afford $300 powder meter, when I bought my RCBS uniflow new on eBay for something like 50-60 bucks and it works pretty darn good! Maybe I can add micrometer or something to it, also need to experiment with seating depth. What kind of scope do you use? I find that even on 24x it’s hard to see tiny bulls-eye at 100 yards.

      2. For Load development, I used to use a Sightron 10-50 x 60MM target dot scope. Now I have the new Vortex Eagle 10-60 x 52 scope. The high power allows much better target resolution (unless there is a lot of mirage), since I can see down to about 1/8 inch. I always put these high power scopes on every rifle when doing load development, then once I have my “best” load worked up, switch to whatever scope I intend to use on a regular basis for that rifle. For example, my hunting scopes are max power of 10x or 14x. Shooting the same gun and load with the lower power scope usually opens my groups up by 0.5 – 1.0 MOA, simply because the target resolution is so much less. You are right that at 24X power a .224 hole is difficult to see at 100 yards, which is why I also use a 60X spotting scope when I am not shooting with a higher power scope.

        If you are considering a “better” gun, you might consider a Savage with the Accutrigger. If you look at my handle (Savage Shooter), I have found that this brand of bolt gun gets you amazing accuracy for a relatively low price. I own five of them and they all shoot sub 1″ with factory Hornady Match ammo. As a matter of fact, I really had to do a lot of load development to beat the factory ammo.

      3. I don’t do enough shooting to justify $1500 scope, it would be nice though to try one out. I own Savage laminated 93R17, I was disappointed in the quality. First when I put my own scope and rings I’ve noticed I had to max out windage in one direction, it looked like plate was tapped wrong and I wasn’t only one with that problem. Second, the magazine started ejecting all rounds, spilling them, when you attempt to chamber first round. Third the magazine is made from piece of sheet metal, super simple construction and they want 37 bucks for it!! But the stock is nice, I wish my 223 had stock like that. I saw 12 LRPV Left Port on youtube once and I though that was pretty cool, the way it ejects to the left, but it’s too expensive for me.

    2. Yeah… The spread is logically going to increase with the more rounds fired. But I’m looking for a single-digit SD, so 20-25 fps spread over 3 rounds is never going to qualify for that.

  3. It helps that I I live out and have a 100-yard range in my back yard. I load 5 and shoot; I adjust from there. Some very good points were made in this article; consistency is king! I commend the author.

  4. Thanks for this article. Gave me some things to think about and try. Article was deep enough but not too deep. Great post for this style of communication.

    Never heard of a Harrell’s powder meter. Will check into that. Thanks!

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