3 shot groups

[todbartell]

Fired nine 3 shot groups with a Tikka T3x CTR 223 at 215 yards into one big group, just disected it all with the Shotmarker electronic target. 69gr Sierra TMK over Varget, in Nosler brass

Hornady's sample size podcasts have suggested 3 shot groups will vary 65% from the average (1" avg, expect groups from .35 to 1.65")

Let's take a look :

Group 1 - 1.13moa

Group 2 - 1.02moa

Group 3 - 0.59moa

Group 4 0.48moa

Group 5 - 0.49moa

Group 6 - 0.66moa

Group 7 - 0.74moa

Group 8 - 0.55moa

Group 9 - 0.33moa

Total group - 1.36moa

3 shot groups averaged out to 0.66moa, so using the 65% variability rule, 3 shot groups could be expected from 0.23moa to 1.09moa. I experienced groups from 0.33 to 1.13moa

 

[Joel]

Fired nine 3 shot groups with a Tikka T3x CTR 223 at 215 yards into one big group, just disected it all with the Shotmarker electronic target. 69gr Sierra TMK over Varget, in Nosler brass

Hornady's sample size podcasts have suggested 3 shot groups will vary 65% from the average (1" avg, expect groups from .35 to 1.65")

Let's take a look :

Group 1 - 1.13moa

Group 2 - 1.02moa

Group 3 - 0.59moa

Group 4 0.48moa

Group 5 - 0.49moa

Group 6 - 0.66moa

Group 7 - 0.74moa

Group 8 - 0.55moa

Group 9 - 0.33moa

Total group - 1.36moa

3 shot groups averaged out to 0.66moa, so using the 65% variability rule, 3 shot groups could be expected from 0.23moa to 1.09moa. I experienced groups from 0.33 to 1.13moa

How about that! Interesting test, props for seeing that through.

They'd be way more consistent if you just threw out your filters tho /s

 

[todbartell]

Follow me for more recipes and fun tips as we squash the validity of 3 shot groups

 

[BlackPowderBurner]

The funny thing is the people who would benefit most from your presentation won't understand it.

 

[L.Parratt]

Reloading All day made a really good Instagram post about this aswell

hope this link works

Ive found large sample also matches up pretty closely with Bryan Litzs top gun thoery

For the rifle from this 20 round group

0.005×(2,029÷17)+0.039 = .636

 

[tony d]

Awesome test thanks

 

[708fan]

10 shots touching and 17 all over. A good start. You should be able to recall reticle movement premuzzle flash, the feel of the torque/recoil through your shoulder+grip hand+cheek and recognize those differences between the 10 and 17, make the necessary adjustments and dispense with the nonsense from Hornady.

 

[MRP]

Shoot 20, pick the best 3.

 

[DGY]

Good shooting!! I will be following this for sure!

 

[FatCatsDad]

I see no bipod, what shooting stance did you use ?
Same for each group ?

 

[Dogleg]

There’s 3276 possible unique 3 shot groups in a 27 round group. If you’re one of those guys that believes the order of the hits is important on groups there’s 19,656 combinations.
The density of the core of the 27 round group is consistent with a bell curve, or normal dispersion. You could drop 27 empty shell casing on the ground and they would form a “group” most of which would be close to the center.
A group is a sample. The sample has to be big enough to accurately predict where the rest of ammo supply would go or it doesn’t mean much.

 

[apexanimal]

I shoot 1 round groups, sub MOA every time.

 

[Paul_T]

The density of the core of the 27 round group is consistent with a bell curve, or normal dispersion. You could drop 27 empty shell casing on the ground and they would form a “group” most of which would be close to the center.
A group is a sample. The sample has to be big enough to accurately predict where the rest of ammo supply would go or it doesn’t mean much.

I'm wondering how Hornady came up with the 65% rule - I would expect 68% or one SD because of the bell curve distribution.

 

[todbartell]

I'm wondering how Hornady came up with the 65% rule - I would expect 68% or one SD because of the bell curve distribution.

They say 60-70%, I just split the difference