This makes an interesting read on how JSB actually produce the pellets:
The interesting part for me is where its talked about each machine die has as many as 10 holes for producing pellets and there are 54 swaging lines in the factory .... so if I read it correctly, up to 10 holes from one die, is that why we get so many dirfferent head sizes in one tin produced from the same die?? (since 10 holes are being used at a time) If any of the tooling has to be changed, the resulting pellets fall into a new and different die lot.
I have the following tins of JSB's pellets:
34000013 0 4.52 with a very deep piercing
34000013 1 4.52 with a medium piercing
39007010 0 4.52 with a deep piercing
39000011 0 4.52 with a very deep piercing
39007412 2 4.52 with a very deep piercing
Also have some Daystate Sovereigns that were all purchased in 2013. The first ones purchased were mega, but the second and third ones were nowhere near as good and performed differently in the same gun. Since Daystate do not put a die and batch numbers on their tins nowadays, if difficult to know what you are actually getting!