Small ES and SD But !!!!

[AlNyhus]

I think what Henry's testing shows us is to not believe much of what you read on these forums.Lots of well intentioned but misinformed people offering up bad advice and quoting bad sources as gospel.

Lynn, I couldn't agree more. A lot of the stuff you see posted on different forums is just the same old wives tales that have been repeated so often that they have somehow become 'fact'.

I'm a pretty serious tester and try to do things in as scientific a manner as possible. But at some point the testing has to stop and we need to prove our theories in registered competition. That's where we find out if we're just 'talkin' the talk' or if we can 'walk the walk'. No excuses, no could have/should have/would have stuff. Just us, the target, the clock and the other competitors. And at the end of the day, we get to see how our ideas, theories and testing have stood up against others that are all doing the same thing.

Good shootin' to all.

 

[tripcrow]

Here are my last 3 ladder tests. Two using the Crony that Midway has on sale for $79. The other’s from an old $100 Shooting Crony that I put a bullet through a few months back. While I’m not a statistician, using some fuzzy math you can see the probability that these chronographs have a 1% shot to shot error is somewhere in the light year realm. While the probability that it has a ½% error is in the chance to win a big lottery realm. I’d say these numbers show that even the cheap cronies have at most a .2% and more likely a .1% shot to shot error. Now that doesn’t mean that it isn’t reading a consistent 30-50FPS,or 1%) off of actual speed on any given day or in any particular condition. But for load development purposes consistency is what I’m mostly after.

New 8 twist Broughton, 6BR, Kelbly Griz2, Master Class stock, 36X Big Sky Sightron, 268 neck, 300 meters, 70F, no wind, 105VLD Berger, Varget, CCI SR, Lapua brass, 3 shot groups.
load %fps ES SD group
29.1 2738 29 ?? .93”
29.4 2790 27 14 1.05
29.7 2799 40 20 1.67
30.0 2823 23 12 .88
30.3 2843 24 ?? .76
30.6 2885 15 8 .88
30.9 2906 44 23 1.41
31.2 2945 10 5 .94

Factory 9 twist 223 Winchester HV, 36X Weaver T36, 300 meters, 80F, 10MPH erratic wind ignored, 75VLD Berger, Varget, CCI SR, Lapua brass, 3 shot groups.
load %fps ES SD group
24.0 2812 50 29 1.58”
24.2 2833 30 15 1.03
24.4 2871 48 24 2.06
24.6 2894 28 15 3.77
24.8 2935 42 26 2.80
25.0 2945 7 4 1.74
25.2 2963 17 9 1.73
25.4 2966 27 14 1.16
25.6 2997 23 12 1.50
25.8 3021 11 5 2.03

8 twist Brux, 6X47L, Kelbly Griz2, Master Class stock, 45X Leupold Comp, .268 neck, 200 meters, 49F, 0-5MPH wind ignored, 105VLD Berger, IMR4350, CCI SR MAG, Lapua brass, 3 shot groups.
load %fps ES SD group
38.5 3031 3 1 .51
39.0 3061 33 17 .75
39.5 3111 15 8 .81
40.0 3152 12 6 1.28,pulled big {dang Ship benches})

So because of luck you can have a small group and high SD. But show me a small 10 shot group at 400+ yards with a SD of 20+. It just ain’t going to happen but once a millennium.

And yes you can have a large group with a low SD. Bad lot of bullets, bad crown, conditions, shooter error…… And a bad SD doesn’t necessarily mean a bad load. Could be bad primer, media in the flash hole or case, lube…..

And there’s plenty of times that I’ve shot 7-8 shot groups with the same load on different days and got very close to the same results SD wise.

Edit: Photos added, 6BR & 223 superimposed onto 1 sheet for keeping. 6x47 not worth the time.