Okay, so there is two questions. First, does anyone have any experience with the .223 and Hornady SXSP bullets in 55 grains? I am looking for bullets to load for coyotes and rockchucks, and I am curious how well they work. My second question has to do with powder. A very common thing I have read about reloading is to start with 10% less powder than a maximum load and work your way up. How small should the increments be as I am working up to the max load? Do I go up by a half grain at a time, or should it be less? Thanks for any input.
Loki
Loki.....It depends on how many different loads you want to test, how many shots per group, and how many cases you have to do it with.
For example, if you have 25 cases, and you intend to shoot 5-shot groups, you simply space out the powder increments equally between your minimum and maximum loads. Say, your minimum is 26gr, and max is 30gr, you can test five, 5-shot groups at 26, 27, 28, 29, and 30gr.
Once you've done that, you may want to test once more. Say your best group was at 29gr. You can then do it all over again spacing the increments equally between 28gr and 30gr......28.0, 28.5, 29.0, 29.5, 30.0gr.
That'll get you pretty darn close to your optimum powder weight for your rifle using that particular bullet at that seating depth, using that primer.
Depending on how you want to slice hairs, you can further test seating depths, primers, case prep methods, and so forth.....but for general shooting and hunting, the second testing of powders is ususlly good enough to find a decent load for most applications.
(Note that I usually begin experimenting with bullets seated to about .010-.020" ogive to lands, when I can. This is usually pretty close to the seat depth that produces the best accuracy for me.)
HS