I figured I'd take some time to share how I go about tuning a new rifle intended for long range hunting. I'll say up front I have tried every method out there and have settled on this one for a few reasons. First, it works. It has always provided me with loads that perform. Its fast and easy. Most times I can tune a hunting rifle in less that 20 rounds. I have 100% faith it the method, when I was still competing in 1000 yard Benchrest I would shoot a ladder the night before every match and load exactly what the ladder told me. That year I set 2 group aggregate world records. It would not have happened without the ladders.
When you get your new rifle, load a light load and go put 100 rounds on the barrel. Use this time to get the scope setup, break in the barrel, and learn the rifle. Most barrels will change in that first 100 or so shots and you will be re-tuning if you find a load right away. I have been down that road so many times that I just dont try and cheat it anymore. You should also take some cases and work up .5 grains at a time until you hit pressure (stiff bolt lift). If you MUST do some load work before 100 rounds just play with seating depth but dont fall in love. Once you have that first 100 down and you know where pressure is in your barrel it time to load a ladder test. I would have to assume we have a basic knowledge of what powders, primers, and bullets seem to work well in the case we're loading for. I will usually pick 2 powders and load ladders with powder charges spaced .6%. So for a case that holds an 80 grain charge you would go in .5 grain incidents. Load about 10 cases ending just under your max. Example for a 28 Nosler with an 89 grain max
84
84.5
85
85.5
86
86.5
87
87.5
88
88.5
Usually this will show you your upper node and the next one down. I didn't mention seating depth. Here I will say I usually always find accuracy just in or just off the lands. I will start with a seating depth that I know that bullet seems to like. Certain bullets do in my experience seem to like the similar seating depths across many rifles. I will list a few examples
215 Breger Hybrid .010" off
195 Berger Hybrid .015" off
300 Breger hybrid .015" in
180 Berger Hybrid .020" off
If its a new to me bullet and there is no good data I will usually start .010" off, unless its really long like the 300 or 230, then I will put it .015" in. For some reason those long heavy bullets have responded very well to being in the lands. I have never pulled a bullet, I do not use very light neck tension. I have found most rifles will shoot best with more. I typically start with .003". Do nothing to the inside of your necks other than brush with a stiff nylon brush, do NOT remove the carbon from inside your necks.
Im no writer and have bounced around, but I will tell you how to perform the ladder now. So you have your 10 loaded cases. Color from the ogive to the tip with a sharpie. Blue, red, green, and yellow are best. Record the colors so you know what they are and you will have to repeat their use because we dont have 10 colors to use. But you will be able to tell what are what, as the hotter ones usually will climb the target. Use your judgement on the range at which to shoot. If things are decent I will go to 600 if they are not great I will go to 300, but never less. You need to use your chrony for this. Use a clean white piece of paper, butchers paper works well or the back of a target. Fire all the rounds at the same aim point. adjust your scope so they print off to the side so you can read them better. With ladders we are looking for bullets to climb, then for 2-3 shots to stop and form a group before starting back up the target. Those spots where the shots level out also have to correspond with a flat spot in velocity to work for a hunting rifle. We are looking for the spot the barrel has given us leeway in load variations as well as a flat spot in velocity which will provide us with good ES. You then pick a powder charge in the middle of that flat spot and adjust seating depth if needed to achieve the accuracy your after.
I must note that this method requires a well built rifle that is capable of good accuracy. We are depending on the rifle to pet every shot where it should go. I would not recommend shooting a ladder with a 1moa rifle, there will be too much built in vertical to make sense of it. Also you must be capable of breaking good shots, and choosing a day worthy of testing. If you test on a bad day with highs winds or mirage you will end up chasing your tail. It does not need to be perfect, but it needs to be decent. This was a lot of typing but I guarantee you if you do it in a controlled manner you will love the accuracy and efficiency of the process. Im sure I missed something, but Im just tired of typing at this point. Im happy to answer any questions...
