I know we always say that you find the right batch for your barrel etc and that's true.
However I believe there will be batches that are just poor and maybe won't do well in any barrel.
The 18's I have had a lot of bent and poor looking tails. AA say that that doesn't matter ... they will straighten when seated and fired etc.
I was getting really poor groups with these 18s. So I inspected them and removed all the dodgy looking tails and it improved things. I even thought we were back to normal with a few decent groups. Then the groups were just not great. Inch groups at 35y. 3 or 4 decent ones and then flyers again. I inspected the pellets as I loaded them and they looked ok ( this would be second visual ) and they felt ok going into the barrel. Groups still not great and I just thought I must be having a really bad day.
Before I went home I tried what was left of some old tins ( 21 ) and the groups tightened right up back to normal.
So I don't know whether it's just that batch 18 that don't suit my barrel or whether 18's are just sh1te.