There is definitely something to be said for practicing the drawing of a pistol or the shouldering of a long gun as a kata. It is known that when using the so called african carry (muzzle down rifle behind shoulder weak side) a long gun can with practice be deployed just a wee bit slower than a pistol from a strong side holster.
Jeff Hall has developed a "martial art" centered around the use of firearms. My instructor, Steve Mc Daniel (who helped inspire the stryle)is an associate of his, I can ask him more about this.
In addition to the presentation of the weapon, use of the firearm as an impact weapon would also be worht studying in arefined manner.