How tight a group?

Hornady posted this fascinating video on statistical group size variance based on their testing. The takeaway is people think their equipment is way more consistent and capable than it is based un statistically insignificant sample sizes.

So many people think a good 3 shot group means they have a "(small group size) MOA rifle" when that usually is far from the case. The example from Hornady:

If one shot ten 3 shot groups with the same rifle/ammo setup, the expected variance up and down from the average to the biggest and smallest groups is 60-70%. So if the average group size at 100 yards across ten 3 shot groups was 0.5", the smallest is expected to be around 0.15" and the largest is expected to be around 0.85". If the average group size were 1", the smallest expected would be 0.3" and largest 1.7". And I guarantee there's a lot of those 1" average group guns that are "Half MOA guns" on the internet all day with a picture of their 0.3" group.. start around the 30 minute mark for these details if you want.

The other glorious thing about this video is it helps expose the nonsense dogma people follow on load development. Hopefully people can learn from it and stop wasting time endlessly making small tweaks and trusting statistically insignificant results.


Most hunters suck at shooting. Most people get fooled into believing they and their rifles are a lot better than they really are based on small sample sizes. Those good groups and shots seem to stick in the memory bank more than the bad IMO. We need to stop throwing out the bad as if they weren't a norm in the realm of possibility the next time a trigger is getting pressed.

Edit to add: this points out how rifle manufacturer accuracy guarantees are a joke. "1 MOA 3 shot group guarantee" with the stats shared by hornady means that a rifle that has an average group size of 2" is probably going to give you at least 1 group of less than 1" if you shoot 10 groups! Haha, I can see it now, rube ships rifle back to manufacturer because it shoots like shit, manufacturer ships back with a 0.9" group and note that says "shoots tighter than guaranteed to".
 
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Hornady posted this fascinating video on statistical group size variance based on their testing. The takeaway is people think their equipment is way more consistent and capable than it is based un statistically insignificant sample sizes.

So many people think a good 3 shot group means they have a "(small group size) MOA rifle" when that usually is far from the case. The example from Hornady:

If one shot ten 3 shot groups with the same rifle/ammo setup, the expected variance up and down from the average to the biggest and smallest groups is 60-70%. So if the average group size at 100 yards across ten 3 shot groups was 0.5", the smallest is expected to be around 0.15" and the largest is expected to be around 0.85". If the average group size were 1", the smallest expected would be 0.3" and largest 1.7". And I guarantee there's a lot of those 1" average group guns that are "Half MOA guns" on the internet all day with a picture of their 0.3" group.. start around the 30 minute mark for these details if you want.

The other glorious thing about this video is it helps expose the nonsense dogma people follow on load development. Hopefully people can learn from it and stop wasting time endlessly making small tweaks and trusting statistically insignificant results.


Most hunters suck at shooting. Most people get fooled into believing they and their rifles are a lot better than they really are based on small sample sizes. Those good groups and shots seem to stick in the memory bank more than the bad IMO. We need to stop throwing out the bad as if they weren't a norm in the realm of possibility the next time a trigger is getting pressed.

Edit to add: this points out how rifle manufacturer accuracy guarantees are a joke. "1 MOA 3 shot group guarantee" with the stats shared by hornady means that a rifle that has an average group size of 2" is probably going to give you at least 1 group of less than 1" if you shoot 10 groups! Haha, I can see it now, rube ships rifle back to manufacturer because it shoots like shit, manufacturer ships back with a 0.9" group and note that says "shoots tighter than guaranteed to".
That was an interesting video. It would be a tough pill to shoot 30 rds to 'zero' a rifle, but I understand the reasoning. I think practically a 10 rd zero is prob fine for average hunting ranges, <400 yds. If you are going to shoot farther you should prob commit the time and ammo to get a good reference data set. Thanks for the link
 
That was an interesting video. It would be a tough pill to shoot 30 rds to 'zero' a rifle, but I understand the reasoning. I think practically a 10 rd zero is prob fine for average hunting ranges, <400 yds. If you are going to shoot farther you should prob commit the time and ammo to get a good reference data set. Thanks for the link
Something to think about. Are you testing the rifle or yourself? If testing the rifle I shoot off sand bags in front and another small squeeze bag in the rear. If I'm testing myself, I get into the best field position I can and shoot at objects at unknown ranges. Guarantee the rifle's I have will out shoot me! But some of the precession from the rifles comes back to roost with me and the only thing that can improve me is me! Best shooting rifle I ever had was a 222 Rem in a mod 788. From a bench it would blow up sugar cubes every shot! Pretty hard time hitting them from field positions though! We all have this built in handicap, we are human!
 
1.5" at 100 yards is pretty good, and is roughly what most of my rifles would do in the past, some a little better. But if you're spending a lot of time and money on a high end hunting rifle and handloads, I sure prefer better. I don't use a bipod or bench anymore when doing handload testing, just prone over a backpack. My new 6.5 is shooting a lot better than 1". Most of my testing so far with the rifle has been at 300m, as that is where the scope is parallax free. On a calm day, I can hit a pie plate sized target over 1000m. Here's some 5 shot groups at 186m, handloads on left, hornady factory ammo on right. When the weather's right I can get around 2" groups with arrows at 100, so I sure hope an expensive rifle will do better.
12E92BBB-1ADF-4D0D-BA73-C979D3C61B79.jpeg
 
That was an interesting video. It would be a tough pill to shoot 30 rds to 'zero' a rifle, but I understand the reasoning. I think practically a 10 rd zero is prob fine for average hunting ranges, <400 yds. If you are going to shoot farther you should prob commit the time and ammo to get a good reference data set. Thanks for the link
I didn't get to that part yet, will watch the rest tonight. I'd agree though that I'd have a hard time seeing notable error with a 10 shot group if the rifle shoots decent and you're probably fine with less if the rifle shoots tight for hunting purposes.
 
Something to think about. Are you testing the rifle or yourself? If testing the rifle I shoot off sand bags in front and another small squeeze bag in the rear. If I'm testing myself, I get into the best field position I can and shoot at objects at unknown ranges. Guarantee the rifle's I have will out shoot me! But some of the precession from the rifles comes back to roost with me and the only thing that can improve me is me! Best shooting rifle I ever had was a 222 Rem in a mod 788. From a bench it would blow up sugar cubes every shot! Pretty hard time hitting them from field positions though! We all have this built in handicap, we are human!
I always shoot the rifle from a "field position", laying down off a bipod, so back bag. To me there is no benefit to shooting from a sled or something, the rifle is only going to shoot as well as I can so might as well set realistic expectations at the range.
 
Oh, my favorite topic! Well almost my favorite topic.

I shoot 2-shot groups. But it is not so much, how many shots per group, but how many groups, and what you do with the data that matter. For those that want to go there, I offer this. It is not like anything you have seen before.

If you don't like it, that's fine too.
 

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When my uncle was alive, he would collect milk and juice jugs, then fill them with water and hang from limbs at different locations and distances around the ranch from 50-350 yards
and we would practice our field shooting with our hunting rifles
only rest was a tree , rock, sometimes a bipod
good exercise for big game , no turret or lazy ars range
 
For factory loaded HUNTING ammunition fired out of a FACTORY hunting rifle, anything under an inch I feel is acceptable. I picked up some Norma 300wsm 180gr and put four boxes through two different rifles yesterday and both rifles shot every group under 1moa. I only do 3 round groups because the barrels heat up so fast, the only difference I noticed was the Kimber fps were slightly higher than the Tikka.
I mainly bought the ammo just for the brass, but would have no qualms hunting with this ammo.Ballistic-X-Export-2022-12-15 15_05_05.848494.jpgBallistic-X-Export-2022-12-15 15_03_13.808737.jpgBallistic-X-Export-2022-12-15 15_01_46.255236.jpgBallistic-X-Export-2022-12-15 14_59_47.625699.jpg20221215_150624.jpg
 
I always shoot the rifle from a "field position", laying down off a bipod, so back bag. To me there is no benefit to shooting from a sled or something, the rifle is only going to shoot as well as I can so might as well set realistic expectations at the range.
Good point!
 
The benefit to shooting from a bench is establishing what the rifle is capable of, say 1 MOA. This is now your baseline to then establish what YOU are capable of.

If your gun will only do 2 MOA off the bench with bags, then 2.5 MOA under field conditions is pretty good. I’d your gun is 1 MOA off the bench with bags, 2.5 MOA under field conditions isn’t so good.
 
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