This is a Birminham action. They make incredible little varmint rifles - .17HMR here. Buddy has his in .17Ackley Hornet & I am tempted to convert mine to the same. tis rifle takes gophers to 240 yards when required, but usually I try to stay inside 200 yards. At that range head shots are capable - amazingly accurate rifle - little or no wind, 3/8", 5 shot groups 100 meters (FOR A RIMFIRE!). Good actions are needed for that kind of accuracy and the Martini does it.