vfc Avalon fps issues

[gonzala]

alright, so I picked up a second hand vfc Avalon calibur dx. The gun had never been gamed and according to the previous owner he had ordered it from redwolf with the level 4 400-440 fps power upgrade.

copied from the redwolf site level 4
1. Install Prometheus spring;
2. Systema Steel bushings;
3. Prometheus Steel gears;
4. Battery Compartment Mods;
5. Systema Directional Piston Head;
6. Fuse removal;
7. Custom work to ensure smooth operation;
8. Install Deep Fire Titanium Piston (Titanium Teeth);

I haven't opened the gearbox to check any of this but I can see the warranty sticker is cut in half

when I first chronoed the gun it shot a consistent 380-390fps on .2s so I figured I'd dental floss the bucking and put a couple orings on the barrel to see if I could bump that number up a bit. I switched to my .28s expecting to see about 330-340 fps but ended up at 280fps with a drop to 100-150fps every 5 rounds or so.

so I figure I have an airleak between the gearbox and hop chamber seeing as I haven't messed with the gearbox. I've reseated the chamber, taken the inner barrel out, changed the amount of orings, changed the bucking, retied the floss, multiple times. the only thing I haven't done is put everything back to stock and retest. which I'll have to do tonight. so far I'm down to 1 oring on the inner and the new bucking tied and I'm at a low but fairly consistent 300fps with .28 but still with the occasional big drop.

the only thing making me paranoid right now is 2 nights ago I had just tied the floss and put 3 small orings on the barrel. the upper and lower were very tight to put back together but I managed to pin it. before I could test, my girlfriend needed to go to the hospital and the gun sat like this over night. could I have damaged something with the hop chamber pushed against the gearbox so tight? the chamber seems fine when I look at it.

I'm kinda at a loss here, there's more testing I need to do tonight for sure like put the barrel group all back to stock. I wasn't planning on going into the gearbox as I hadn't messed with it and I don't see how it could have developed an airleak overnight but I'm not sure anymore. any ideas would be appreciated. thanks.

*update*
alright, so I went into the gearbox to test the compression and everything seems good. there are a few scratches on the inside of the cylinder but nothing major, still gets good airseal. I touched up on grease and closed it up.

something new I've noticed, with the 2 mag 190rnd midcaps I picked up i see 180fps with jumps to 310 with .28g and with my buddies g&g hicap I borrowed for test purposes I'm getting fairly consistent 310fps which is still low. I was originally hitting 380-390 with .2g with the mag midcaps so I should see about 330fps on a .28g. now my mags are an issue as well? I've never dealt with something like this, I'm about ready to send it to someone with more tech experience. also sorry about the mixed weights but I ran out of .2g bbs.

[lurkingknight]

does the piston slide freely in the rails when the gearbox is screwed shut?

[gonzala]

turns out the prommy spring redwolf put in was shot. a fresh spring did the trick.