Wed Sep 26, 2018 9:07 pm
Can't help you with that batch. As you haven't yet had a response (apologies if this is stating the obvious) I thought you might be interested in my findings: the best place to start, if unable to get the same batch, is another batch from the same die.
I have a bit of an obsession with testing different batches... over 50 JSB-manufactured, plus various others, in last 2 years, in several guns. Generally I've found no difference between different batches from the same die. In some cases I've found the same die number sold as different sizes (e.g. Weihrauch FT Exacts 4.51 die 8 and JSB Exact 4.52 die 8) to be indistinguishable by my measurements - head diameter, length, weight and trajectory (POI and group size at 30m and 50yds). I started this testing in an attempt to find alternatives for a very pellet-fussy rifle, thinking perhaps I could draw some conclusions from weight and dimensions. The measurements are not entirely successful in predicting performance but they can narrow down likely candidates.