JG Full Stock with QD mount
 

So I have a King Arms M4 and I want to get a full stock for it for battery space/personal preference. Ideally, I'd like one with a built in quick detach mount, but I've only found them from JG. I've had issues with stocks not fitting before, so I wanted to make sure it would fit before I ordered one online.

Yes a King Arms M4 is pretty standard. You can also get stock/receiver plates that have a QD attachment like this:

http://shop.ehobbyasia.com/gandp-kac...-m4-aeg-1.html

That wouldn't work for a full stock.
Me personally knowing the "quality" of JG plastic, would not trust a QD point drilled into the plastic like that. It's just asking to get your stock cracked.

There are some M16 sling adapters out there. Rare but they're floating around somewhere. You're looking for something like this:
http://www.airsoftoutletnw.com/media...2/0/2029_5.jpg

http://m.airsoftmegastore.com/237-AC...kyo-Marui.aspx

There ya go.

Stealth, oh yeah missed that but you provided an example.

Yea I was figuring probably the same thing on build quality. The only one I'd found around was the one Dutch linked too. I'd definitely prefer the style of the one Styrak posted (the push button release, I know it won't mount to a full stock). If they don't exist/are too hard to find I'll just try and find one of the one you posted there.

Basically, the sling I use is an IRENE adaptive, and it's just faster and easier to hit a push button release rather than dick around with the mash-clip.