Read this before you start the process of working up a load for your new rifle! It could save you huge amounts of time and money… Find out more!
Spring is around the corner. Well, if you walk way out into the street and squint really hard you can at least think you see it… Well it’s coming soon enough, at least, now’s a good time to get ready.
I never have been big on the personal value of published load data. The data I’m referring to is that from propellant and other component manufacturers, and also from articles done by independents. I think all such information, at most, provides a place to start, and it also gives some ideas on tendencies and cautions, and provides means for comparisons. But. I don’t think it can be taken straight to the loading bench with any guarantee of success, or of attaining “advertised” performance. And I say that not because I don’t think these folks don’t know what they’re doing. They do! It’s because, after way more than enough experience in proving myself right, I can tell you absolutely that their rifle is not your rifle! Neither, necessarily, are their propellant, primer, case, or bullet. Always take careful note of the barrel and components used for any published test data, and compare them to yours. In later comparisons of my notes with published data, sometimes I’m higher, often times I’m lower, and enough times I’m way lower… That’s the main concern there.
It’s not at all difficult to learn to develop your own loads, to essentially write your own loading manual.
To do this efficiently, you need to learn to load at the range. Right, right there near to where you’re testing. An unremarkable investment in a few tools and a little creativity can provide a way to take your show on the road.
The reason to do this is because it provides a way to precisely chart results. It’s a more reliable and accurate way to proceed. Otherwise, the option is to load varying charges at home and then see what happens at the range. That’s okay, but not nearly as good as on-the-spot experiements. Plus, you won’t have left over partial boxes of poor-performing rounds. It’s more economical and way on more efficient.
The preparation part, and this is what you might spend the remaining cold month or two working on, is, first, to get the tooling ready and, second, and most important, to start making notes on your powder meter.
Important: To be able to work up at the range, it’s mandatory that you’re using a meter that has incremental adjustment. Either a “click”-type “Culver”-style insert or, at minimum, a micrometer-style metering arm. You’ll be relying on the meter, not scales, to progress upward in propellant charges, and you absolutely have to know what the values are for each increment using the different propellants you plan to test. That is where you’ll be spending time prior to doing your homework. It’s well worth it! It can be a nightmare trying to get scales to read accurately outdoors, including the digital type.
Equipment List and Set-Up
When I need to do load work, I size, prep, and prime new cases and put them in a cartridge carrier (usually a 100-round box). I then pack up my little press, seating die, my meter, some cleaning gear, C-clamps, and my propellants. The press and meter and cleaning gear go in a tool box. I usually carry the propellants in a picnic-type cooler. And, very importantly, my chronograph. A notebook, some masking tape, and a sack lunch… I might be there a while.
Always (always) use new cases for load work-up.
When I get to the range, I’ll clamp-mount my press and meter to a bench, get out all the rest, and set up the chronograph. Take a target downrange and tack it up. I test at 300 yards, unless the load is intended for shorter-range use. I initially test longer-range loads at 300. Maybe I’m lazy, but longer-range testing is a tad amount more tedious. I’ll come back for that after I have a contender or two.
Working Up The Load:
The reason it’s a “work-up” is clear enough: we’re almost always looking to get the highest velocity we can, safely. High velocity, or higher velocity, is usually all-good. Shorter flight time means less bullet drift and drop, and a harder hit.
So working up means increasing propellant charge until we’re happy: happy with the speed and also that the cases will still hold water. (And more about that next time…)
Very important: it is vitally necessary to have established a goal, a stopping point, prior to testing. That is one of the functions of published data. That goal is bound to be velocity, not charge weight. And that, right there, is why you’re working up at the range: you want to get “advertised” velocity and need to find the charge weight that produces it.
I work up 0.20 grains at a time. Sometimes it’s more if I’m reading an unuseably low velocity on the initial trial. Since my meter has a “Culver”-style insert, which I trust completely, I reference its number of clicks in my notes rather than the grain-weights (a Culver works like a sight knob, and reads in the number of clicks, not the weight itself). I check the weights when I get back, and I do that by clicking to the settings I found delivered, and then weighing the resultant charges. Otherwise, just throw a charge into a case and cap it with masking tape (clearly labeled).
It’s not necessary to fire many rounds per increment. “Mathematically” 3-5 rounds is a stable enough base to reckon the performance of one step. Of course, I’ll be shooting more successive proofs-per-trial once I get it close. Some folks, and especially competitive shooters, wear out a barrel testing loads. That’s not necessary.
Here are 3 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. I fire my most important rounds after 60+ rounds have gone through it, so I want a realistic evaluation of accuracy and velocity.
2. Replace the cases back into the container in the order they were fired. This allows for accurate post-test measurements. Use masking tape and staggered rows to label and identify the steps. I use 100-round ammo boxes because they leave enough space for the tape strips.
3. Go up 0.20 grains but come off 0.50 grains! 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…