He's not sure jumping on the damn thing would be the smartest thing to do at this point, not if people were going to openly fire at it. (Last thing he needed was to get shot again.) But he will take a gun. He's never used one before—Evoker aside—but he'll attempt one anyway. He can any of the heavier models, probably handle the recoil better than anyone else.
And it's not like he's chasing after a small target.
Shinjiro > Gun
And it's not like he's chasing after a small target.