First Airsoft Gun Malfunction!

[ThatGnomeGuy]

I think I've heard it said that if you play Airsoft, your gun will break at some point. Maybe no one said it; maybe it's too obvious. Anyway ...
I've been experimenting with optics for the G&G L85 carbine I bought at the end of January. I'd found and purchased a replica SUSAT for it online (no one had that weird stuff on-shelf locally). The SUSAT worked great. I used it on Saturday at The Swamp, where my chronograph readings were disturbingly low (320 FPS/0.20g) compared to spec info (370-400 FPS/0.20g). This got my spider sense tingling, but like a teen with a suspect car, I kept on keeping on.

Recently, I found a Madbull A3 railed fore end for it, which gives me the option of running forward-mounted optics. Tried an EOTech -- made the gun too front heavy, so I grabbed a SIG RDS on an AR-height riser. It looked OK on there and the weight distribution was good; I decided to sight it in.
Inserted a mag, took it outside, aimed at the plastic bowling ball in the back yard, and pulled the trigger. The gun made a whirring noise and vomited BBs onto the deck. I reseated the mag, flipped the selector up and back down, and pulled the trigger again. More whirring, more BB vomit.
Called Extreme Velocity to check whether I'm still within G&G's warranty period (I am) and arranged to get it in for a "looking-at" tomorrow. I should be bummed, maybe, I dunno. I'm kind of glad I've been using it and enjoying it enough to get to this point. Use = love, right?
And so begins the journey of repair, possible upgrades, etc.
Shameless plug: the gang at EV have been quite helpful to this particular noob.

[Dennis - Crossbow]

Shameless plug: the gang at EV have been quite helpful to this particular noob.

No shameless plug! Extreme Velocity are AP Sponsors and its important to share your positive experiences

[Rentax]

It's hard to say without having all 5 senses on it... Taste is especially important when I have done tech work... Yes I am joking... But different things sound different, how the gun reacts is important as well. It sounds like maybe a partially stripped piston, the gears are rotating but not making full contact so they whine/grind, and the gun short cycles with very little compression, so the BB's roll out the end of the barrel. But that really is just a guess.
I'd be interested to know what they say.

[ThatGnomeGuy]

The sound was less grind and more what you'd expect to hear if there just wasn't any air being pushed around. Tasted a little like fun, a little like failure. Smelled like "nooooooooo!" If I understood Dillon(?) the tech correctly, the air cylinder lost compression. I'm not certain, but it seems like the piston itself didn't strip.
He had a spare on hand, threw it in, and it is back up and running -- all in about two days' time.
I thought I'd be down for a long while, as warranty work is a thankless (and largely profitless) job, but they got it up, running, and back to me in almost no time.
He casually mentioned that a steady diet of F/A fire is the usual cause ... I quickly looked away, even though we were talking on the phone. The L85 really begs to sit on full auto and dispense bursts and strings, so I'm figuring on more trips to the gun doctor are in my future.
Again, EV is a damned good group of folks.