The KWA mechboxes are very nicely built right out of the box.
The solid aluminum piston head is a mistake, IMHO, especially since it is not loc tite'd to it's screw.
The shell has been beefed up near the front...with more material than other version 2 shells. What kind of extra-strength and breakage prevention this provides...couldn't tell you.
I've not seen one break yet...but most have been either shot stock or downgraded to high/mid-300's. Several bags of bbs through each one.
My next build with one will be a low 300fps high speed rig. Nothing over 9.6v...8.4v likely. I'm confident that it'll run for a good long time (or break right away
).
With a properly built mechbox (components scaled to power, well shimmed, not used in extreme temperatures, etc...)...v2's can perform extremely well for tens of thousands of shots.
But the cheapy clone setups...or the ones cobbled together with crappy cheap parts....well, you get what you pay for. Keep in mind that the cheap stuff runs $70-100 overseas and costs much less to produce. That's getting near disposable...use it for a game, burn it out, toss it and buy a new one. The company has already suceeded in their objective...you've bought it. You're fooling yourself if you think they care one iota about how long it lasts you.
Am I a KWA fan-boy? Not really. No more so than I think G&G, CA and a couple of others have put out good products. I do think that KWA missed the boat on a couple of key points in producing their armalite model:
1. Retaining the split hopup design
2. Requiring a "unique" top hopup unit and nozzle
3. Metal piston head
4. Non-loc-tite'd grub screws that secures the barrel to the chamber (at least there's 4 of them)
5. The ridge on their body stub for the stock tube is annoying.
Other than that...nice build.
Tys