Actually all saw chain has irregular drive link pin spacing. You
actually measure the pitch by measuring the ditance across _3_ pins
C/C, the dividing by 2. See? Easy and sensible! G

Please tell me that's what you mean!

Yeah, something like that. I was looking into this some
when I bought a chain for my dad, so now I've forgotten
all the particulars, but it's not unusual for the nominal
pitch to not match any particular single link in the chain.
Though I want to say that in the larger pitches, they actually
do match. I'd have to dig back into the Oregon site to figure
all this out again, but it sounds like you're on top of it.

--Glenn Lyford