is it racist if i blame it on him being italian
(you know i love you really @Skara )
to my eye (caveat ofc that it's just one photo) it wouldn't hurt to shift it back a bit, not too much though.
i'd also be sure to check the piston isnt rubbing on the gear- that extended rear tooth looks like it might be rubbing.
if, like me, your objective is perfect accuracy then the air seal is never good enough
hard to say, but i have had boxes *cough*lct*cough* that needed as much as 1.5mm of shims.
that's admittedly on the extreme end but not unheard of.
personally i like these kits from ak2m4:
https://www.ak2m4.co.uk/internal-parts/bushings-shims/xt-shim-set-etched
because it's real handy having them marked what they are.
^this
can't say i've ever opened a stock marui box to see what their stock aoe is like, but i reckon it's less about design and more about manufacturing tolerance, or lack thereof.
plus it's possible that in the very early days marui didn't put in as much effort as they would now purely because they wouldn't have known what they were starting/didn't think it was going to take off like it did, although take that with the huge pinch of salt required for one guy speculating on the internet.
must admit not heard that one before, although certainly i can see them not bothering to correct something that wouldn't be an issue with a sub 1j gun being cranked by 90's spec nicads.
yep, the issue with aoe correction the impression given that it needs done to every gun, when the reality is some guns need it, some don't, some need a little, some need a lot. the "5mm of sorbo minimum in everything" school of thought is as ridiculous as suggesting every gun needs 2mm of shims on every gear to work properly, which is the message i think folk like yourself and negative airsoft are really trying to get across.