Boris - Yes sir it is removable. The stocks are removable for all shotguns, except the few made with a one piece polymer stock and receiver (Made in Turkey). You can install another stock, a pistol grip, a folding stock, or one of the birds head type grips like the shockwave uses.

Boris, it is Sir since there is a "Pistol Grip" option for this exact shotgun. https://dkfirearms.com/product/mossberg-500-persuader-20ga-20-8rd-with-pistol-grip-kit/

Hi Boris, No unfortunately it isn't removable on this model.