first thing I do now is check nozzle actually fits the hop unit
sounds daft but some shs m4 red nozzles can be a smidge tight fir in G&G stock hop
check hop unit is sealing in hop - just them 2 items first
you should be able to feel the seal blowing down barrel with a ultra light press on nozzle in hop
next when you are starting to redo the box with tappet+nozzle in there
insert hop unit up against box correctly like it normally would in gun - check seal again
seal is crap it "may" indicate front of tappet could be shaved or sanded down a tiny slither
thus pushing the nozzle a tiny bit more foward to seal against hop bucking
other checks include with tappet/nozzle fully retracted ensure the nozzle is clear of hop feed tube so bb can enter ok
if not then additional work required to allow nozzle to travel back a smidge further
this is bit more involved as you need to check the sector's cam can pull back the tappet a little more
if not then the hop can be pushed forward with some electrician's tape on front of box to ensure the nozzle clears for bb to enter
but this would lessen the final seal against hop bucking so you need to check how much you can push tappet forward
basically the tappet/nozzle moves aprox 8mm or 9mm or so in total
what you are trying to achieve is getting that "window" of movement in the exact perfect position to allow bb's to feed easily
and also to seal perfectly against bucking.....
A piece of cake it sounds but unfortunately so many smidges of variations occur between various parts fitting together properly
small variations in nozzle lengths, tight fit in some hops, different hops can make a huge difference sitting either side of "window"
even down to the tappet plate's ridge where nozzle clips in - some have ridge in centre, others a tiny bit forward/backwards.
Oh yes it is a major bollock ache sometimes but it is where taking a bit more time checking everything bit by bit really pays off
the 416 was a major headache and a big learning curve getting that sod to work properly - but now is running very nicely
(jeez bet she busts now I said that, but so far it is perhaps one of my best builds to date)
on average a box rebuilt every 3 or 4 weeks and still I'm learning more n more n more with every box
is why I say 25% good parts & 75% care & attention to detail is what works for me atm, - so far anyway
always check and double check stuff before you pick up the file or dremmel or piece of sandpaper
but as of yet I haven't need to file nozzle but instead check & "adjust" the tappet movement/travel
