I’ve owned more than half a dozen of these in various chamberings, including .20 Mashburn Bee, .22 Hornet, .218 Bee, .218 Mashburn Bee, .219 Zipper, .256 Winchester and .357 Magnum. The three of those which weren’t bushed when I bought them all needed bushing and got a trip to the gunsmith for same. Perhaps some original Cadet actions don’t require bushing the firing pin, but I’ve never owned one other than an original .310 Cadet which did not.