No it makes you proficient with what you have.
This is somewhat of a loaded question. What kind of guns are you talking about? I have found that switching back and forth between rifles/pistols and then shotguns, or vice versa causes issues. This is because the techniques involved in shooting the different types of firearm are completely different. A shotgun is a point and slap the trigger firearm, Rifles and pistols are aim and press the trigger while keeping the sights aligned. Being primarily a rifle and pistol person I gave up trap shooting because I can't hit the broad side of a barn aiming and squeezing. The only thing that I use a shotgun for these days is turkey hunting because aim and pressing the trigger works well under those conditions. My humble advice is choose one type and stick with it.
