0
Any weapon in Single Player mode
This trick works for primary weapon only. First, set your multiplayer weapon
preferences up. Then, when you have the desired primary weapon chosen, go back
and select single player. Choose your mission, but do not press the right and
left arrows next to the primary weapon on the weapons confirm screen. While the
mission loads, the bottom of the loading screen will say you have the default
primary weapon, but when the mission loads, you will have the primary weapon you
have chosen.
This trick works for primary weapon only. First, set your multiplayer weapon
preferences up. Then, when you have the desired primary weapon chosen, go back
and select single player. Choose your mission, but do not press the right and
left arrows next to the primary weapon on the weapons confirm screen. While the
mission loads, the bottom of the loading screen will say you have the default
primary weapon, but when the mission loads, you will have the primary weapon you
have chosen.