How I now do it.

[Clem Bronkoski]

This is how I now do my load development and so far it is working really well. First I select a powder that will fill my case to the base of the neck with a max charge and gives me respectable velocity. Next I load 3 rounds of each charge from 1 grain over starting (I never found that the starting load is acceptable) to 1 grain over max in 0.3 gr increments. These are with the bullet seated at the recommended COAL stated in the manuals. I wait for a windless or very low wind day and shoot these 3 shot groups waiting 3-5 mins between groups. If your loading technique is good you will see your group sizes getting smaller until they reach a point and will start increasing again. Note all shots are measured including so called flyers.
Now that I've selected a powder charge I begin to work on seating depth. I start at 0.03" under book OAL and continue in 0.03" increments until I'm touching the lands or reach maximum length for my magazine. I load 3 rounds each at these OALs.
Using the same method of shooting a 3 shot group and allowing to cool for 3-5 mins between groups.
One thing I found using this method is that if you're not satisfied with your results a component change may be necessary. It may be your choice of bullet or even your primer. But only change one component at a time otherwise you won't know what the culprit was.
Using this method I have two Savage Axis rifles shooting sub 1/2 MOA which is truly remarkable.
Now I know some of yo may recall the trouble I was having with my Bergara 300WM but it turned out this was a combination of a faulty scope and a cheap muzzle brake. Both of which are in the process of being resolved.
Now you can take this with a grain of salt because I'm no long range expert by any means nor am I any longer a competitive shooter. I shoot solely for my own satisfaction and to improve myself. This method is working for me. Ever since I was a kid I loved rifles over shotguns because I like the challenge of sending one projectile downrange and having it go exactly where I wanted it to go no matter the range.

The target below is showing only the different powder charges all at the manual's recommended COAL. Next outing I will be adjusting seating depts. This is with a Savage Axis in 6 ARC. What a fun rifle to shoot!
Top center target had one fouling shot then started shooting groups. You can see the first and second group size difference was substantial and the third group shrunk to 0.271", then the groups started growing. Next outing I will be tweaking the seating depth and its very possible that the manual's depth is perfect for this rifle.

 

[ShtrRdy]

To double check one of your numbers ...... when doing seating depth testing you wrote that you use 0.3" increments. Is this correct?

 

[Clem Bronkoski]

To double check one of your numbers ...... when doing seating depth testing you wrote that you use 0.3" increments. Is this correct?

nope 0.03" thanks
BTW: I just started using the masking tape cross on plain cardboard. This allows me to perfectly center the crosshairs in the center of the tape's intersection for more precise shooting.

 

[nksmfamjp]

Do your groups repeat? Have you ever shot the same 3 shot groups 2-3 times on different days?

Once you find your best, have you ever shot 20 of one group of your best and a 20 shot group of your worst? How do they compare?

 

[BRADMOTO]

Tell me you're bored on a Sunday afternoon without saying you're bored on a Sunday afternoon… Bit too TLDR right now, but I'll circle back on this later…

 

[Clem Bronkoski]

Do your groups repeat? Have you ever shot the same 3 shot groups 2-3 times on different days?

Once you find your best, have you ever shot 20 of one group of your best and a 20 shot group of your worst? How do they compare?

Have you??? Once I find my load yes my groups do repeat or at least very similar. There are other factors involved from day to day. Wind, humidity, temperature even the shooter or the lighting all can cause a difference in groups even if ever so slightly. Load conformation is checked with 5 shot groups not 3.
Also, once you get so many rounds down the barrel you will begin to get throat erosion and will have to lengthen your OAL.
And my only competitor is myself. I don't care about shooting competition. Been there, done that many many years ago. IMO shooting is like golf - its a game you can't win.