I’ve found 5 shot groups do not give me reliable data on expected group size for 22LR. 10 shot groups seem to be a bit more representative of what I can expect from a selected ammo.
Typically, I will shoot 5 X 10 shot groups and take the average of those before I feel I can judge the ammo.
The 5 shot at 100m was just to get some zero'ing data and it was getting too wet I just wanted to get some data before my targets got too soggy or ripped off!
I certainly don't disagree. There's no doubt more data is always going to be a more accurate representation. Not sure if I remember right but I think I read somewhere that in one 500 rounds experiement, average group size of randomly picked individual 5 shot groups were about 50-60% confidence level versus the overall 500 rd group size and 10 shot groups were somewhere around 60-70%. 50 rd groups were in the 70-80% region but the problem with that experiment versus normal guys is that they tested indoor on a vice.
For me, shooting outdoors, the wind and shooter position probably changed more during the 50 rd group to cause the shift in POI versus the actual inconsistency of the ammo/rifle, so five 10shots is probably the best reasonable way I agree.
Only issue on 10 shots for me is that at 50m, I am likely going to get a big hole and can't track all individual shots, so I actually like 5 shot groups and then overlay them on each other using the POA and in the same order as I shoot them. (In reality I usually just eyeball that...)
On a practical side, because my local gun shop only do RWS and Eley, for me the exercise was more about picking between those and also have a look at Lapua/SK to see if it's worth me driving out to get those. Given RWS seems to give me realibility issues in feeding and Eley was was giving pretty good results, it was good enough for me to decide to go with that.
I still have a few boxes of SK match and the Lapuas left. Now that I've narrowed it down to SK Match, Lapua CX, Midas+ and Tenex, I can probably do some 10 shot groups the next time I am at the range but then one can also argue about the lot to lot differences and get into a whole other can of worms... (I do live within an hour drive of the Eley test range, so...)
Also need to do some test with the new chassis when it arrives tomorrow and experiment with action bolt torque as well. All good fun as part of the journey.