Reply To: How to decide what size pellet sizer is needed
First, my Gen1 Marauder (stock barrel) shot the 10.3 grain JSB Exacts nicely, setup for about 850 ft/sec.
Now, I’d say they typically come at 4.51- 4.53 (have not seen any at 4.48?) nominal, these days you may not see them sold in specific head size. The Air Arms pellets are also good, they have a thinner skirt. IMHO, the compression of the skirt is not nearly as significant as the head diameter, and I don’t think you need to be concerned.
Try sorting the pellets by head size, and shooting test groups with the sorted pellets. You will likely see some opening of the groups (and POI shift) when you move plus or minus 0.02 mm from the nominally “best” size. For competition shooting, sorting can improve a score somewhat. If you are getting pellets with really high variance 0.03 mm or greater, you might find some difficulty with the entire tin. It does happen, even with good brands.