Show your Tikka ten round groups

[Tommyhaak]

Except you never get to 100% certainty, since you aren't shooting 100rds at one target. You always have something less than full confidence, especially when you're testing with only ~10rds per load. So then the question becomes, how quickly can I increase confidence in this metric I'm using to evaluate loads? And the answer is to use data from every single shot, instead of just the extreme 2 shots. The formal term here is statistical power. Using shot radius data gets you more power for the same number of shots.

I’m looking for a circular group/pattern that fills in comparable to a Gaussian distribution. The more rounds I fire, the larger the pattern/cone, and the greater confidence I have in the mechanical capability of my weapon/ammo combo. Why not fire 20, 30, or 100 rounds into the same group to gain confidence in actual performance? Then, I care about my worst two rounds to determine actual capability. MR doesn’t give me this information, and delivered by itself, is useless for judging hit rate at distance or capability of that weapon/ammo combo.

 

[Formidilosus]

The load on the left will put more shots closer to POA. We happened to get a big outlier in this example. They both have the same ES (according to my sketching abilities). MR tells you this story where ES doesn't. Agree that if you want to characterize the effective accuracy of the system, you need to look at mean + 2-3sd radius OR ES of a meaningful shot count. As I've discussed many times before, tracking individual shot radius data and using mean + sd method will get you to the "correct" or "true" answer in fewer shots than ES method. However you can get the "correct" answer with both methods.

ETA: For comparing loads with smaller shot count groups, say 10, using this more "information rich" metric will give you a more accurate comparison. So for example (not perfect numbers but illustrates the point), 10rds of radius data is equivalent to a 15rd group ES in terms of telling you the real performance of the load.

That is not correct. You and every one else will zero off the cluster of shots, ignore the “flyer”, and then that flyer- is way off POA and falls outside the expected cone.

ES people zero off the center of all rounds, and all shots fall within the expected cone.


You are math dorking for the sake of math dorking. I have long history with this well before the last couple of years where certain groups are pushing it. There is “the math says…” And then there is- “reality on target in the field, shows…”.

I don’t have to math dork, I don’t have to convert, I don’t have to guess, or anything else. Shoot 20-30 shots, zero to center of all shots. Done. And at the same that 30 rounds tells me the 95% probability in MOA. 30 shot 2 MOA ES, at a base if I am missing 2 MOA targets- it is me, not the gun.