Kevin Stenberg
Well-Known Member
Yesterday i did a ladder test on a 223 rifle. I was testing Varget and some 62 gr. jacketed bullets. All charges were hand weight. Loading was done in 1 sitting, in sequence, and all loaded the same way (to the best of my ability)
I had 2 test groups. 1 loaded to feed from my AR magazine. Their loal was 2.188, which was in the middle of the canalure. The other group was loaded to chamber length for my Handi 2.283. All loads were shot in my H&R Handi.
My test was not to test group 1 against group 2. But to see the speed increase of each powder increase within the group.
Group 1 powder weight 21.7 to 24.9 in .2 grain incramants. Group 2 powder weight was 23.5 to 24.9 also in the .2 gr. incramants.
The question i had was concerning an uneven rise in velocity. It happened 3 times in group 1. An not at all in group 2. After thinking about it for a while. I am thinking the velocity fluctuation was simply Standard Deviation rearing its ugly head.
An example is shot 1 at 21.7 grains powder gave velocity of 2428 fps. Shot 2 at 21.9 g.p. was 2383 fps. Shot 3 at 22.1 g.p. was 2415 fps. Shot 4 was 22.3 g.p. with a velocity of 2470 fps.
Would this lot of 4 shots be a node?
I had 2 test groups. 1 loaded to feed from my AR magazine. Their loal was 2.188, which was in the middle of the canalure. The other group was loaded to chamber length for my Handi 2.283. All loads were shot in my H&R Handi.
My test was not to test group 1 against group 2. But to see the speed increase of each powder increase within the group.
Group 1 powder weight 21.7 to 24.9 in .2 grain incramants. Group 2 powder weight was 23.5 to 24.9 also in the .2 gr. incramants.
The question i had was concerning an uneven rise in velocity. It happened 3 times in group 1. An not at all in group 2. After thinking about it for a while. I am thinking the velocity fluctuation was simply Standard Deviation rearing its ugly head.
An example is shot 1 at 21.7 grains powder gave velocity of 2428 fps. Shot 2 at 21.9 g.p. was 2383 fps. Shot 3 at 22.1 g.p. was 2415 fps. Shot 4 was 22.3 g.p. with a velocity of 2470 fps.
Would this lot of 4 shots be a node?