Things I liked: I have found that these bolts work exceptionally well with my Crosman 1377, American classic air pistol on all targets. Since that gun has a rifeled barrel, the fins fit the grooves and the dart will fly further and straighter.
Things I would have changed: 4 Petals have to be cut in the solid plastic just below the metal tip to aid in attaining a higher velocity to fire the bolt. Before they were redisigned the petals were molded in to the darts body.
What others should know: They work very well to kill pests of all type.