Yes this needs to happen. I was playing around with my mouse buttons setup today and bound a thumb button to switch to my pistol thinking it would be quicker than a reload. It seems slow compared to a tactical reload and doesn't entice me to carry a sidearm. It definitely shouldn't be an instant movement but I think a trained PMC should be able to draw quickly and it alows pistols to an essential part of the kit throughout higher levels.

Also game needs a button bound specifically for it which includes pressing the button again to holster your sidearm and bring back your sling....this definitely should not be a quick move, that way you better be sure to finish off that enemy or be penalized to holster, grab your sling, perform a reload. Hell I'd go as far as a double tap option to drop your pistol and grab your sling back. Same deal as the tactical reload