Thread: 3 shot groups are useless!

Originally Posted by whanahuia

I think thats what a few of us might have been arguing.

I think the difference is in what we consider the limitations to be, and what we consider wasting time/ammo.


I consider that 3 or even 5 shot groups taken in isolation don't tell us enough to be meaningful IF we want to make an accurate statement about our rifle system's performance, IF we wish to understand the effects of "load development" OR if we wish to have higher confidence in hitting things consistently at longer ranges, and it's much more efficient and wastes less time/ammo to just shoot enough shots to gather enough data to be better informed. If our interest is limited to shooting deer at a couple of hundred metres, these discussions are probably not the right ones to get involved in, as it is explicitly not about that subject.


My suggested approach is to do less fiddling with things that don't give us any real evidence - just get a good amount of data and go use it. 3-shot seating depth tests, 3-shot powder charge tests, 3-shot zero then trying to shoot long range and "true" BC or muzzle velocity - all are more likely a waste of ammo and time.

Note that also "gathering data from more shots" doesn't mean you have to go fire 10 rounds back-to-back if you're worried your rifle will "walk" or "open up" with that. Shoot 10 individual shots with complete cooling in between. Actually record where they fall and plot those relative to each other.

There are a series of good questions that arise from this thread that those who have an interest in gaining a clearer understanding of the technical aspects could empirically test with data for themselves, and the wider benefit of the community. Some of these that come to mind are:


- How consistent is the POI of a "cold bore" (fouled or clean) shot, and does a meaningful sample of these look any different from the dispersion of the same number of shots from warm barrels?

- Does barrel heat actually change the dispersion of your rifle system? Or is it simply that a larger number of shots gives a more true picture of the true dispersion?

- What is the actual precision capability of your rifle system? How well do groups of various sizes represent that?

- What is the actual velocity, and velocity variation of your rifle system?

- How well zeroed actually is your rifle?


I don't mind shooting a few rounds at the range to help build the knowledge of the community and I don't consider it a waste



I have spent enough time around shooters in situations like LR target shooting days to observe that the average shooter's self-assessment of their ability to hit things at longer ranges consistently is usually not based on much evidence, and is much higher than reality. Aside from shooter proficiency effects and junk gear, the next biggest issues are poor zero and poor data.