Diffrences in German 7.9 labels

I’m in the process of going through a lot of German labels on 7.9 boxes, and noticed that some boxes of one lot- number can be quite different. I was quite surprised to see that. I would have thought that all labels and data in one lot was identical, but it’s not. Many times it’s the primers that has different lot, but one label had two very different way in layout, and all component where different. A few examples attached:

Lot P. 491 4. L. 40 Different primer and powder lot:

Lot kam. 1. L. 41 Different primer, bullet and case lot :

Lot P. 207. 39. L. 38 Different label layout, different primer, bullet and case lot. Different powder.

Is this known that some lot’s of ammunition did contain different powder, different primers and different bullets? I would have thought that one lot should contain no variables, but it seems that one lot was just about production numbers? I have more boxes of the same lot with different component lot’s.

If you look at the specifications (Technische Lieferbedingungen), it becomes obvious that the acceptance process very much revolved around the components:
Bullets of each lot were assembled into complete cartridges and fired for acceptance.
The same with each case lot (and I presume primer lot and propellant lot).
Specifications clearly stated that “surplus” cases left over from a previous lot could be used with the current case lot in a single cartridge lot.

Acceptance “lot size”, at least later in the war, was not by cartridge lot number, but the cartridges produced during one shift. You can see that inside the wooden ammunition cases the date and the shift is rubber stamped. Independent of acceptance shooting by the local Heeresabnahmestelle, a (small) sample of each shift “lot” had to be sent to Kummersdorf or Zeithain. Only after an OK was received, the “lot” could released to the military. How closely these rules were followed in wartime is another question.

All in all, the acceptance process was quite different from what we are used to today.