Going to South Dakota in October, question is, I will be taking two rifles, can I also put my hand gun in with the rifles. Ammo will be shipped before the flight.
Yeah, as long as all normal federal regulations are followed. The process for declaring a firearm should be the same. But just to throw it out there, what about the handgun in your regular luggage to diversify and reduce chances of theft of all your guns at once?
Firearms can't go in a carry on. Put the handguns in your rifle case. Some airlines have a limit on how many you can pack in a case, ie AA is 3 long guns and 5 pistols per case. No case limit. Ammo 11 lbs max.
Follow TSA and your airline guidelines and you'll have no problems.