Re: What is your method of working up a load?
First a few important considerations.
Does the rifling match the bullet. A lot of times, if you have a standard twist, it won't stabilize the longer, heavier bullets and you won't get an accurate load, no matter how many things you try.
Do you have runout issues? The RCBS casemaster is priceless as far as telling you if your ammo is concentric or not.
I use nothing but Redding Competition dies. My finished ammos is maybe .002" bullet runout to give me a firm foundation for a load.
You probably know this, but prep the brass. Deburr flash holes, full length size, trim to length, turn necks, deburr case mouth inside and out.
Beyond that... here we go.
Pick a powder and primer that should work in your case. I think, but haven't tried it yet, that maybe you'd want to pick a moderate powder charge and shoot some 5 round groups with some different primers. Chronograph them and see which gives the lowest velocity spread.
What I actually do is use a CCI BR2 for "standard" calibers and either a Fed 215 or CCI 250 for mags.
I've recently started using the "ladder test" for load development, and so far it seems to work great. Start with a middle of the road charge. Load one round with that and then increase by .2 grains for the next round. Keep going in .2 increments until you've reached the max load or close to it. I number the rounds.
Shooting over a chrono to chart the speeds, shoot round # 1, 2 and maybe 3 (all from 200 yards or so). From then on, you have to watch the barrel temp and not let it get too hot or the test is for nothing. I chart the bullet impacts on another target back at the bench. I fetch the target and then number the holes. Looking at the target, you should find 2 - 3 that are in a pretty tight group. Load 5 round groups around those charges and you should have something that shoots pretty darned well. From there, you can tweak the seating depth to center the load in the sweet spot.
If you don't like the velocity range you're getting, switch powders and try it again. I've had 165s traveling 2950 that shot great and 180s going 3250 that shot great. The only problem is that the first was too slow for a 300 WBY and the second too hot. Back to the drawing board this spring with another combo yet!
Hope this helps.
All it takes is One Good Shot!