Alright, well, problem solved, or at least, I'm 80% sure lol, not going on 100% yet. On the bright side, I do enjoy solving problems like this, granted it's usually electronics, and now I know my gun pretty thoroughly, except for the trigger assembly.
First things first, turns out the gun already had an npas valve in it, awesome, I need to see if I can return the one I bought and just buy the tool, as I don't need a spare vale (I'd rather put the money towards a nice ish optic or some mags.
Second, I got some m3 washers and shimmed the mags with two each, this ended up not being good, the gas seal at the top of them has had a bit of contact so I only used two washers to shim the mags, I could unshim them completely but I'm not totally confident in that.
What I did which seems to have really fixed it is shim the magwell, I saw in one video somebody had done this to fix the feed issue, so I cut the magstrip out of an old gift card, cut it down to fit nicely in the lower section on the right that you can see in the image below. hit it with some sandpaper and used some CA glue. The magazines are nice and tight now and sit a little bit higher up at the front.
This worked really well, after about 40 shots or so my repaired nozzle cracked again so I replaced it, moving the npas valve over to one of my two spares, part of the back section was cracked off too so that probably didn't help with it's alignment.
I've put around 90 rounds through now and I haven't had a single issue, she's purring like a kitten, except for when I put the npas in and accidentally set it to vent most of the gas making the bb's basically drop after 6 inches lol.
I can't say it won't break another nozzle any time soon but I finally have a good feeling lol.
I remember seeing some sticky white cloth ish stuff in the magwell when I got it, I took that out figuring it was some shipping crap, but thinking back the mag was in there so that was probably shimming by the previous owner, d'oh.
Anyways, time to clean out the factory lube, use some 20wt silicone in some areas and a thin coat of lithium grease for the bolt to really get her in nice operating shape.
@BioRage, I did see the aluminum nozzle and almost bought it but apparently they have issues sealing sometimes, and don't work well with npas, and it would risk breaking something else if it misfeeds, instead of snapping the feed arm and preventing further damage, in theory.
I do want to get a tan modify bucking or something similar, don't know if that's the maple leaf one you speak of but that's on my list for sure.
Also, bio bb's are required at our fields IIRC, and personally I don't mind spending the bit extra to not put a bunch more shitty plastic into the environment
@Danke that input about the metal nozzle is helpful though, have you had any issues with sealing? Not sure if you speak of the aluminum one, or a steel one I read about once I think, the main thing I saw with the aluminum ones is that they would bend upon a misfeed. Smashing the bb to bits would be preferable to a nozzle though, and the hopup assembly does feel pretty skookum.
Anyhoo, side note from all this, if anyone knows of a 7.62 suppressor that works with the scar's flash hider thread, in black, that would be awesome, I can't figure out what the large 1 or two turn thread is called, or what that style suppressor would be.