What does this feature actually do on weapons?
Sorry if this has already been discussed, I'm new today

It increases the accuracy slightly, reduced the recoil a bit, but also increases Chaos (so if you run around with the stock out, it will aim off center more).

For general fighting, its best to keep the stock folded since you will be moving alot, but if you are on defense, its better to unfold it so you have more accuracy.

Actually, the stock doesn't do anything for the guns' accuracy values. It does do the recoil and chaos thing though.

Additionally, for the SAR-12, having the stock extended improves its performance further when crouching with the weapon, with less recoil and faster chaos recovery than with an un-extended stock. It also increases the gun's length, but that won't really factor in unless you're literally shooting at someone at point blank.

It's important to consider your environment and fighting style when folding or unfolding the stock. If you're a run-and-gun kind of guy, and you're in a close quarters map, you might want to keep it folded. If there are long corridors or open spaces or you're more of an aim and shoot kind of guy, you may want to have it extended.

Ok, thanks guys.