Hi ND: When I'm testing I usually shoot over a chronograph and for accuracy at the same time to kill 2 birds. I always start with several powders first with the same bullets. I shoot 5 rd strings at 1 grain increments of each powder starting at a mid level load until I reach max or pressure signs appear. I will try to use brass that has already been shot in that rifle, I think it is a little more accurate than new brass i.e blown to the chamber. Usually I can get a good bearing with just a few powders, and a couple of shots, no need to waste bullets. I can pull them later and use them for practice. If I don't get good groups, but good velocity, I start over again with different bullets, then primers, and COL, etc. Once I get my velocity's/groups where I like I start tweeking/refining the loads. Remember to let the BBL cool and clean as necessary, take your time. When starting with new loads I keep a 3-ring binder with a cheat sheet I made up and copied with all sorts of info i.e. Rifle/Pistol, scope, all load data, velocity's, date, time, temp, wind, elevation, etc then I cut out and tape the target groups on the same cheat sheet to keep for reference later. There are probably a lot of different ways to approach testing, this is just how I do it. I do load for handguns and usually use a Dillon 650 with all the bells and whistles, Some times I just relax and use a single stage press. I have owned the Hornady progressive presses along with the 1050 Dillons and the High speed Ammo Loads, but to be Honest a good single stage press and a Dillon 550B is really all anyone needs. I don't want to ruffle anyones feathers, and have friends that use the Lee 1000 and works for them, but they don't shoot nearly the amount I do so I tend to get higher end reloading equipment. I do like the lee pistol final crimp die and works very well on stuborn cases that won't no-go guage. I live 180 miles from Dillon and bought a used one as a back-up, drove it down to them. they re-built it no questions asked at no charge. In Rifles I tend to use Win and CCI primers, for Pistols. If it's in a race gun with a light hammer drop I use Federal followed by Win. CCI years ago had a bad rep for very hard cups and a lot of guys stayed away from them in their competition pistols as they did not go bang. I don't know how they are now. For rifles they work fine. Federal pistol primers are more sensitative to firing pin impact, and Impact in general, I suppose that's why they don't recommend them, or something in their priming design ? I really don't know. Just a guess. If you want to see primers go off crank up an Ammoload at 5000 rds an hour push the foot petal to the floor, only did that once, they are great with new primed brass, ours had scatter shields. Retired now got rid of the Ammo Loads now back using the Dillons and RCBS. Hope this helped