A collapsible stock by definition is one that is not fixed permanently in length, and it does not fold. The collapsing movement is achieved as the stock extends or retracts in a straight line from the weapon.

Is a collapsible stock legal?

The first concern of purchasing folding stocks is the legality of the accessory, which can be murky because the federal laws on guns do not have any explicit regulations on them. Following this logic, folding stocks are not illegal to own.

What's the point of a collapsible stock?

A collapsible (or telescoping) stock makes the weapon shorter and more compact for storage, carrying and concealment, and can be deployed just before shooting for better control.