Dean Mundy
ArboristSite Lurker
Cheers kiwi bro!Yes. It's quite typical of Chinese origin chains to have significant inconsistencies. Get a good one and it makes you feel quite smug about the savings made. Until you get a few schitzo loops.
Using a grinder does help at least ensure everything is set consistently but it in no way ensures cutters wear reasonably consistently. For extra credit, mark the cutters that seem very soft and the ones that seem very hard. Then check the wear patterns of them for differences over time.
I've given up on Chinese chain and despite the cost have settled on Stihl chain, with just a few non-stihl chains left in the quiver to work through.