Originally Posted by GotGauge

What type of Gun? Handgun, Rifle, shotgun?

Gun Shows you can get weapons the same day, I believe they still do call for a Back Ground Check, but not 100% sure on that.

Gun stores, you can get Rifles or Shotguns the with a simple form they call in and do a quick back ground check on you. You only need to be 18.

Walmart here sells Rifles and Shotguns, again with a quick form and a phone call if approved, it takes about 10 minutes.

Handguns, I am not sure on, except you must be 21. Last time I purchased one there was a 3 or 5 day wait.

All my answers are based from Kansas.