Use of wadding in a smooth bore gun rifle 'produces all except -
Functions of wad are:-

(i) It separates the projectiles from propellant.
(ii) It seals the bore effectively.
(iii) It prevents expanding gas from escaping, and
(iv) It allows optimum pressure to develop.

The felt wad is impregnated with grease and this lubricates the bore.
Causes fatal injuries
Helps in lubrication
Optimum pressure
Sealing the air