Tuning: Part 1 = Keys to Tuning
Updated: Dec 2, 2022
Having a tuned rifle, at a Benchrest tournament, could be the difference between bringing home some wood or finishing in the middle of the pack. In a hunting situation, a tuned rifle could be the difference between a lethal shot or a non-trackable wound.
You need to have a tuned rifle if you want more than just a lucky chance at hitting that prairie dog at four hundred yards or a “hung up” coyote at two fifty. True, if a whitetail is forty yards away in the timber, tuning probably is not on the top of your to do list. However, move that deer out past three hundred and it changes the story. Having a tuned hunting rifle will increase your confidence in making a quick, clean, ethical, kill shot.
In short range Benchrest, there are two main classifications; group and score. At a group tournament, it is all about precision. Group shooters are trying to shoot the tightest groups possible, regardless of where the group forms inside the borders, at 100, 200, and sometimes 300 yds. Score shooting is all about accuracy. These competitors are trying to place their shots on a demanding target, at the same distances. In order to perform well in either of those, we need a precision rifle that is in tune.
On the simple side of definitions, having a rifle that is in-tune means that rounds loaded with the same components will place their bullets in relatively the same spot. In other words, your groups will be smaller in a tuned rifle than in an out-of-tune rifle. We could get more scientific with the explanation but we do not need to. You do not have to understand the science of tuning to take advantage of the benefits of it. If you want to shoot smaller groups, you just have to remember a few, basic, universal keys.
1. Keep Detailed Notes.
Write down all the information that was used to create the groups you shot. To be blunt and to the point; every shot you take, while performing load development, should be reproducible later on. Do not assume you will remember all the important, little, details of your load that resulted in a great group at the range.
When you are unsure if you should write something down, then that means you should write it down. That little piece of information may be of huge importance later on. You have to be able to trust this data to make logical decisions during your tuning process. Bad or wrong data is often worse than no data at all.
Here is the Load Development Target that I use most often. This target is how I keep detailed notes and stay organized. Feel free to use this as a guide to make your own load development targets. Good groups or not, I keep all load development targets in a binder with dividers for each rifle/barrel I own.
2. Find a forgiving load.
The main idea for tuning is to find a load that consistently groups well, or is predictable, regardless of changes in conditions. In other words, we want a forgiving load. We do not want to chase that “wallet” group that only worked one time during one day. We are looking for the range of powder charges, seating depths and neck tensions that consistently shoot small. I call this a tune window. The bigger the tune window, the more forgiving the load.
The importance behind finding a forgiving load is that conditions (temperature, pressure, humidity, etc) change. They can change region to region or even day to day. In the Benchrest world; having a tuned rifle means you will know exactly what to do with your load when the temperature changes. Your tune will be predictable. In the hunting world; your tune window should be big enough that you do not have to worry about your group size changing when loading in Nebraska then going on an antelope hunt in Wyoming.
3. Only Change One Variable at a Time.
You need to be able to figure out what caused the good or bad groups when looking for the forgiving load. You should be looking for repeatable trends to get inside of your tune window. The easiest way to do that is to only change one variable at a time. For example; when you change the powder charge, do not also change the seating depth. Changing only one variable will allow you to figure out what that variable does in your tuning equation.
Sound simple enough? Remember, simple does not mean easy. Some days you will be rushed and will keep sloppy notes. Some days will be frustrating and nothing you loaded will group well. Stay the course. Consistently applying those keys, no matter which tuning method you use, and you will find a forgiving load.
If you are a hand-loader click on Part 2 of this Blog to find out my process for finding a forgiving load. More importantly, that blog should help you develop your own routine. If you are not a hand-loader go to Part 3. That blog outlines the procedures for tuning your rifle using store bought ammo. Until next time, enjoy the experience.