Wow, thanks for the kind words chaps. Shooting groups on paper is something I absolutely hate doing because I always end up disappointed in the result.
I was shooting 20x mag Colin. I set my target board out next to the bush that marks 55 yards in the paddock, sat down and range found it on 32x mag - dialed in 55 yards and then changed the mag down to 20x to shoot. I didn't touch the scope after that.
I've re-uploaded the target scans now after putting them through a cool bit of free software I found last night to analyse group sizes (It's called 'On Target').
Turns out the die 19 group is 1.16 MoA CTC, but interestingly the die 45 group is still just a shade over 1" (1.8 MoA) so that's still ok, even though through the scope it looked like a shotgun pattern to me.
I think that illustrates my reasoning for trying to find a less error prone and subjective method of batch selection.
To me, the die 19 group felt mega - out of 10 shots 6 of them had more pellet inside the bullseye than out of it, and like I said earlier the first shot went almost smack bang through the centre of the bull. (a lucky shot)
But... the die 34 group had a smaller vertical spread than die 19 - so perhaps if you removed the little bit of wind there was in the equation, that would have been the better group?
That's my problem with shooting groups as a method of selecting batches... first off, even though you're all being very kind, I don't think I'm very good at shooting groups, secondly, It's not always cut and dried when you analyse the group later on and thirdly as Colin described, the whole psychological thing comes into play as well.
So, if you're mega at shooting groups, you've got access to an indoor range and a bench to rest your gun on - shooting groups has got to be the most reliable method of selecting batches. If that doesn't apply to you, then maybe shooting downrange chrono strings is a viable alternative?
Putting it all into perspective though.. on a day like yesterday on a 40mm kill at 55 yards I probably would be aiming either halfway between centre of kill and left edge or I might have gone inside left edge. Either of those aimpoints would have taken down the 40mm kill on 29 out of the 30 shots I took (die 45 had a flyer low and left which probably would have missed the kill).
So you could argue that just picking up any random tin of JSB's and shooting straight from the tin is as good as you need for FT or HFT. Is careful batch selection going to actually gain you any more targets?... What's it going to give you - 1 extra target out of 50?, 1 out of 100?. Would weighing, washing, lubing, sizing, BiC'ing earn you any more points?... what are we talking, 1 target out of 200. Is it really worth it?
For me, testing 3 batches of pellets over the chrono took me about 45 minutes from start to finish, and about 30 minutes to shoot the groups yesterday. If I'm going to be spending £300-£400 on pellets in one go, I reckon I can justify spending a couple of hours on batch selection even if in real terms it doesn't earn me any more targets at the end of the day.