That's their cover story. They, along with 30 others assigned to their group are going to kill the people at the power plant and then shut it down/blow it up when ordered. Every power grid substation in the country is known by the Chicom's and targeted for permanent destruction.
Maybe you can get them to train their entire terrorist group at your range! Think of all those US UhMURRICAN DOLLARS you'd make, there, prospector! Spend 'em quick, though. They ain't gonna be worth jack squat soon. Whooooooo-dogies!
Come to think of it, they were pretty handy with a .22.
If they really were saboteurs I am sure they could have gotten far better training in mainland China at a specialist training facility than some basic civilian range I the US.