I am restoring my F-I-L's High Standard Model GB .22 LR semiauto pistol for him as a surprise Father's Day gift. These were sold in the early 1950's and usually came with 2 barrels, a 4 inch and a 6 inch. I would buy either length. I am looking for one that doesn't have a divot pounded in the chamber from dry fire, the front sight hasn't been messed with and the blue is still nice.