Fitting new slide and outer barrel/chamber

[Tuthmose]

Hey all,

In the process of fitting and tuning my ProG4 slide and T-K one-piece outer barrel/chamber set, I've run into an issue I'd like some experienced advice with.

The gun works: it fires and cycles reliably. However, it's still not as smooth as it needs to be. If I pull the slide back just a bit and let it go, it doesn't return to battery. Pull it back some more, and the momentum overcomes my "sticky point" and it does return to battery completely.

Seeing as how I have "broken" the edges on the chamber and slide locking lugs, the problem seems to lie in the fit of the hop-up unit to the inside of the outer chamber. It is too tight, and does not move easily. I tested this with just those two parts outside of the gun too, and they ARE too tight. I'm sure this is cause at least in part by my use of the Nine-ball purple Airseal, which being thicker causes the well known issue of the hop-up unit "gaping" at the top when assembled.

Long story short, the question is this: should I sand/file the outside of the hop-up unit or the inside of the chamber? Does it matter which? Or, instead, should I sand the inside of the hop-unit to allow more clearance for the thicker airseal, so the unit closes all the way upon reassembly? Which would be the best way to solve this issue for maximum reliability and accuracy? Is there some other tweak I should consider here?

Thanks advance,
-Tuthmose

[Rock 'N' Roll Outlaw]

Since the outer barrel/chamber serves little in terms of functionality (someone correct me if Im wrong) Id go with shaving that before you touch the hopup. If you notice a problem with fitting the hopup rubber, then maybe you should get a new thinner one instead of going to town with a dremmel.

[Tuthmose]

Thanks, Rock and Roll Outlaw. I'm thinking the outer chamber is the way to go as well, but would feel better about it if one of the GBB pros (Illusion, RacingManiac, looking at you here . . .) concurred. No worries about going to town with a Dremel, thought :-) The fact that it cycles and shoots reliably means that not too much material needs to taken off, regardless of where it comes from.

I've had such good results from the upgraded airseals in my stock Hi-capas that I'd rather not go back to the thinner stuck ones unless it was the only way to solve this problem. They make the hop-up unit gap a bit in those set-ups too, but it looks like the plastic outer-barrel/chamber unit has a bit more room to allow this than does the Tanio-Koba aluminum unit.

-Tuthmose