No, it's not. His explanations are just generalized & are far from any real statistical explanation.
MM
Yes they are generalized, however regal me with how you determine that the gun is mechanically sound and will do the task(s) that you require of it?
You put the "weapon system" i.e., gun scope & ammo into a mechanical rest, fire 30 rounds (fully, compliant, statistically valid sample) & then calculate the standard deviation & perhaps the capability index (CpK).
For example, let's say that the standard deviation (SD) is .5", meaning that the average distance of all shots from the center of the group is .5".
Therefore, 99.7% of all shot fired will be within the circle defined by +/- 3 SD or 3" in this case.
So now that we know the "capability" of the gun (& scope & ammo), we can put it into the hands of the shooter & fire 30 more shots.
If the shooter is as consistent as the machine rest 99.7% of all shots fired will be within a 3" circle determined above; conversely, if the shooter is not as consistent as the machine rest, the group be something larger than the 3" circle.
If so desired, you can now calculate a new SD & capability, as above, for the gun, scope, ammo & the shooter.
When that capability is defined, again, for +/ 3 SD, you can now be statistically sure at the 99.7% level that all shots fired will be within that circle.
For example, with the shooter firing the weapon, the SD is determined to be .75", 99.7% of all shots fired will be in a circle defined by +/- 3 SD or, 4.5" in diameter.
MM
