# of Shots per Group and MOA - Results

Ryan Tockstein

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Apr 28, 2019
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299
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Sandy, UT
Following.

There's a guy on another forum that claims to work at a ballistics facility where they test all kinds of manufacturer's barrels in a mechanical rest. He says that the vast majority of production rifles, even the very highly regarded ones, as well as most aftermarket barrels are really only capable of a true 1MOA and most of the time closer to 1.5 MOA. Barrels that are a true 0.25 or even 0.5MOA are rare. It's just that people don't track their POI through enough shots and they often call shots fliers when they're actually just part of the barrel's accuracy.

He won't give his name or where he works, so I think what he says must be taken with a grain of salt. But, he has shown bits of results of some tests that are apparently OK to show. My guess is that if he's not full of BS, it's a military equipment testing facility because the ideas he's pushing on field accuracy and killing efficacy are related to the probability of making hits at 600yds and the ability to make quick and accurate follow ups. He has also posted about pack testing they've done.

Anyway, this is all very interesting and I think it would do hunters a lot of good to track poi of every shot they make (so long as it's from a barrel that isn't hot with stress placed on it) and use that as their true zero so they're using the actual probability of their rifle/shooter system in determining their abilities to make a hit.

Good post and information. It makes me wish I would have continued my education in engineering!
 

Tommo64

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Nov 29, 2018
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Adelaide
Wow, you really went to town on that one! Good work. It certainly raises some valid points. Clearly, the more shots per group the clearer the picture from a load development and rifle performance perspective. However, I also believe it also becomes as much about the shooter. The more shots taken, the greater the potential for shooter error to creep in. So the need for discipline on his or her part becomes imperative. How many times have we been in that situation where we had a near perfect 4 shot 'clover leaf' only to pull the 5th?
 

LRNut

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Dec 4, 2004
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Arizona/Colorado
Wow, you really went to town on that one! Good work. It certainly raises some valid points. Clearly, the more shots per group the clearer the picture from a load development and rifle performance perspective. However, I also believe it also becomes as much about the shooter. The more shots taken, the greater the potential for shooter error to creep in. So the need for discipline on his or her part becomes imperative. How many times have we been in that situation where we had a near perfect 4 shot 'clover leaf' only to pull the 5th?
What are the odds of flipping a quarter and having it land "heads" three time in a row? One in eight. In other words, every eight times you run through this exercise, you would expect to see this once. The odds of flipping it five times all heads is once in 32. Now, as guys like SpeedEngineer know, a coin flip is a binomial distribution whereas bullet group size is normally distributed. But the same concept applies: if you only shoot a three shot group that plunks into 1/4 inch, you might be misleading yourself, esp if very similar loads (1/2 grain of powder on either end of the "magic" load, for example) group 1 MOA. I do shoot three shot groups when I develop loads, but I verify "good" ones by following up with another at least one day later. I then measure the group size of all six shots.
 
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