Well, I go out to shoot at my favorite spot every Saturday. Usually this is a chronographing session as it was today. I took a few guns and some of the loads I have been working on all week, or in some cases, for several weeks.
Today was the 38-55 model 1893 Marlin with 20" barrel, The Sako AV in 338 Wm with a 22.5" barrel, and the Dakota M76 in 404 Dakota caliber with a 23" barrel. All my guesses for load data were pretty good for all but one particular load for the 338 WM, was exceptional.
I had been working with this and another 338 checking loads side by side and had found an excellent load for the 19.3" carbine and today tried that load in my 22.5" rifle. All shots went into one little hole and the chronograph read M: 2670 fps, E: 07 fps (extreme spread), and SD: 03 fps. This load was a 250 grain Kodiak bonded with 62.0 grains of RL-15 and a Federal 215 primer. The previous load with the same bullet and 61.0 grains of RL-15 was M:2608 fps, E: 39 fps, SD: 16 fps and the group was twice the size of the 62.0 grain load.
Normally I would use RL-19 or H4350 with this caliber/bullet combo but was looking for better performance with the short barreled gun. I had started experimenting with the 250 grain bullets and the faster burning RL-15 powder with the carbine in hopes of getting better velocity and low velocity spread. This did prove to be a good combination but was even better with the 22.5" barreled rifle. I'm usually happy with an SD of less tahn 10 but this was a plus.
Sometimes a blind squirrel finds an walnut!