Logic and physics would suggest 1077 to me, but I suspect this is being shown as an example of rimfire "funny behaviour" so I'm going to go with 1057
That's a good observation.
The higher tenth round was in fact only 2 fps faster than the fastest of the previous nine shots which went into a smallish one hole group.
While this isn't an especially vivid example, it's an illustration that .22LR bullets don't always have a POI that matches their MV.
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Over the last couple of years I've been tracking MV and POI at 100 yards for a number of different ammos. The tracking is done almost always when I use a chronograph to gather infomation about ammo I use when shooting at 100 yards. I do this by recording MV and POI on a paper with a facsimile of the target being shot. Doing this at 50 is much more difficult than at 100. Even then it's sometimes it's quite difficult to tell where the round struck, especially if there are other POI that are close together. I record only those POIs in which I'm confident of location. I shoot when I'm confident that wind is as much as possible a non-factor.
What does the MV/POI tracking show?
It shows that generally there tends to be a relationship between MV and POI. In other words, MV and POI tend to be matching in that faster rounds strike higher on target than slower ones. But it's not uncommon to see disturbingly frequent incidents where MV and POI do not match. Sometimes it's not significant, but at other times, it's quite remarkable how a faster bullet can indeed strike the target with a lower POI than a slower round. And sometimes a round with a slower MV can have a POI above a faster bullet.
And it's not just the vertical component. Some rounds have a POI to the left or right of the POA that is
not influenced by conditions (i.e. wind). At times this is quite significant, so much so that in the
same group it may be possible to see rounds go to both the left
and right of the POA, which indicates wind is not at play.
MV/POI mismatch is more common with the entry level ammos such as the various SK and RWS Rifle Match ammo I've tracked. But more expensive, "top tier" ammos aren't immune from this problem. A MV/POI mismatch occurs with more premium varieties such as RWS Special Match and Lapua Center X and with Midas +. And it occurs more often with some lots than with others. That is to say, some lots have fewer incidents of MV/POI mismatch than others.
If there's interest in seeing some of the MV/POI data please let me know and I can post some of it either here or in another dedicated thread.
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