Originally Posted by skires
... it's focussed my mind back to the topic and why the downrange Chrono tells no lies.
Or can it?
We are suggesting that shooting groups at paper, at range, to pick batches can be confusing because psychological affect could make us shoot with better, or worse, technique, if we start to suspect that that is a good/bad batch.
We are saying that the downrange chrono readings eliminate that. The chrono readings will show that a string with tighter spread indicates that the pellets from that batch are travelling with better stability from that barrel and therefore should give better accuracy.
However, if we are shooting at an aim point, on paper, at the back end of the chrono, then we will see points of impact ... and grouping.
So is it possible that we may shoot a few shots with a certain tin, and they group really well and we see that the readings on the chrono over those few shots are looking very tight. So we now sub-consciously, psychologically, are convinced that this may be a great batch. So we now continue to shoot with, sub-consciously, more focused technique. The group remains tight and the chrono readings remain tight. That must be a great batch!
If we shoot a few shots and the group isn't great and the chrono readings aren't that tight either, then sub-consciously we are thinking this isn't a great batch. So sub-consciously technique relaxes and becomes poor and the pellets are released with some extra instability ... which is not the pellet but the shooter. So now at the chrono end the other pellets in that string go over the chrono with a large spread. Not because the pellets are flying with less stability due to the pellets but because the shooter has released them with less stability. The group on the paper will be poor and we are convinced, also due to the large spread over the chrono that these are a bad batch!
Is that possible ... that the instability of the pellet flight ... and large spread over the chrono ... can be instigated by the shooter releasing them with more 'wobble' of the muzzle?
If that's the case then the downrange chrono testing would have to be 'blind'.
A card placed in front of the chrono readout so the shooter can't see the readings after each shot. You then either use a chrono that records a string that can be read afterwards ... or you have a friend standing at the chrono end recording each reading.
Instead of an aim point on paper just behind the chrono ... the aim point is central at the front top of the chrono and the vertical turret adjusted so the pellets fly a few inches over the chrono but do not hit paper but just disappear into nowhere, so no POI, or group, can be seen.