pinned cylinder mean I'll blow it out if I upgrade it? that mean I should get a more upgradable gun eh?
A pinned cylinder means the cylinder has a pin through the head that will prevent you from disassembling the cylinder. So that means you can't open it, at least not readily. From what I've read, the way you get past this is to destroy the pin by drilling it out. But since you've got an AGML96 (not a viable Maruzen clone), its compatibility with aftermarket parts is extremely limited, if it even exists.
And yes, IMHO, you should get a more upgradeable gun. The ones I mentioned earlier are compatible with well known aftermarket parts by PDI (the best, in my opinion), Laylax, Madbull, and several others. PDI makes stuff that lasts and lasts, but any manufacturer can have a lemon now and then.
Also note, most PDI parts are not compatible with Laylax parts, so a laylax spring guide wont' fit a PDI spring, and vice versa. You need to use all PDI or all Laylax parts once you decide to upgrade. The only exception to this is the Laylax Pss96 Zero Trigger, which is compatible with a PDI cylinder assembly (cylinder, spring guide, and piston). I've got that setup in my own L96.
PDI makes parts for the TM L96... It's just a more intolerant and finicky gun from what I understand.
err, good point. I think I just meant to say that the TM and AGM L96 are not Maruzen clones. Mea Culpa