Maybe some pellet size fanatics can help me with a few little things

Well I certainly feel I have two very fine air rifles, I have really got to know my s200, and how to get the most of it. It likes a regularly cleaned barrel and loves mozzies. They land utterly predictably at all ranges, I suspect a heavier pellet would be better past 55 yards but that is not needed. One hole groups are no bother at all at 45 yards and to be honest it shoots them like this straight out of the tin. I tend to weigh for comps just to give that added confidence, but in the case of this barrel and this pellet, it doesn't seem to matter.
Now the Pro Target is a different story, I feel I don't know it yet. Mozzies seem to group best so far, but i'm sure they are tumbling a little at longer ranges, certainly not quite as accurate as the s200 at the moment. If I give the barrel a good clean and weight the pellets it is much better. So it seems a little more fussy. The only true one holers I have achieved with it at 45 yards is with AA field 4.51, but it wont do it all the time and keeps throwing me surprises, wind aside. So I have been measuring pellet heads with some digital verniers. AA 4.51 seem to average at 4.46mm. It also likes mozzies size wise i'm sure, which are also averaging also at 4.46. I think AA fields may be the magic pellet for the barrel, but i've a feeling to get the magic this barrel will demand them sized and then weighted, cleaned and lubed What a demanding little mynx she is
Right so having endured all that A simple how to question. If i'm looking at trying size's around 4.46, do I just buy a few sizes, 4.45, 4.46, 4.47, squeeze a load of 4.52's down to size, (actually average 4.48) if so what about the skirts, which are presently larger than the heads, wont squeezing them down to the same size ruin the seal in the barrel? Final question for those in the know, who makes accurate dogs dangles sizer sets, and are there different types of methods of sizing, other than vernier calipers, that takes far too long