In the 6th edition, the "Declare Charge" rule specifies that if the unit shot a Rapid Fire weapon then they can't charge.
Tactical Space Marines have a bolter (24ps range) and a bolter pistol (12ps range) as basic equipment.
I understand that within a 12ps range, I can't shoot the bolter (not even as single shot) and charge. I also understand that within the 12ps range, I can only shoot as rapid fire (two shots)
But within the same 12ps range, can I decide to shoot with the pistol and then charge? My understanding would be "yes".