ORIGINAL: AardvarkSlayer
What are some of your reloading procedures for testing new loads? I've been reloading for 22-250 and .257 AI for a few months now and I'm wondering if there's a better way...in other words, I take a minimum powder charge, use it for 3 different groups of ammo with the same bullet, and only vary the seating depth. Once I find the sweet spot for the seating depth for that charge, I then work up the load. That's a great method for finding an accurate load with ONE powder, but then, you have to try different powders to see if you can get it even more accurate. This is where I get confused...Can the seating depth I found with one powder be the sweet spot seating depth also for another powder, or do I have to start all over again and experiment with different seating depths? I do it that way...For example, I'll load 3 groups of matchkings with the same charge of Benchmark powder and vary the seating depth...then I'll load 3 groups of the same bullet with H380 powder using the same 3 differen seating depths, then i'll do the same with varget, and so on....Am I wasting time and money here? should I just find one sweet spot seating depth with one bullet and stick with it for all different powders? Thanks for any help on this confusing question!
I start with a specific powder and bullet, and a "minimum starting load." Then I load three or five rounds (5 for target/varmint rifles, three for a hunting rifle) at that level three or five with 0.5 of a grain more, etc., up to BOOK maximum or a grain or so OVER BOOK MAX. I then go to the bench and test each load, and select the MOST ACCURATE for my further testing. While shooting these loads, I stop shooting at whatever load level begins to show signs of unacceptable pressures!! For a seating depth for these test loads, I seat the bullet to about 2mm off of the lands, or 2mm shorter than the magazine box will permit, whichever is a deeper seating depth.
Once I find the most accurate load by this method, I can then experiment with different seating depths, different primer brands, etc., IF I THINK ACCURACY IS STILL LESS THAN I'M WILLING TO SETTLE FOR!
I will accept groups of 1.25" or less for big-game rifles, and .75" for varmint shooting. I realize a lot of folks want a lot better accuracy than this, and are willing to go to some great efforts to get it! I would too, for benchrest competition, which I have never engaged in! However, using my approach, I have several loads for several rifles that shoot under 1" @ 100 yards, and a couple that will shoot 1" @ 200 yards. One of these is a Ruger No.1B in 7mm Rem. mag., and the other is a M1909 Argentine with no changes except a 3X-9X Bushnell DScopecjhief on it, and it is still a 7.65X54mm.