That is an Old topper model that hasn't been made in years. You don't know if it was born a .357 maximum or as a .357 magnum and modified. It has the barrel ring on it for a sling connection, not my favorite way to mount a sling for the best accuracy, but the biggest reason of all is the condition of this gun on the exterior is very rough at best. That would lead me to question the barrel condition. Did this gun start as a topper shotgun? The scope rail certainly doesn't look to be factory installed. Did someone add a rifle barrel to a shotgun frame against manufacturer recommendations? At $300 I wouldn't buy it, You just have no way of knowing what you are buying. especially when I have purchased 2 H&R Handi-Rifles, .357 maximum, in excellent condition, with a decent scope for $300-$400 this past year. Or purchase a new H&R HandiRilfe in .357 Magnum($275.00) and have it reamed by a gunsmith ($80.00) and have a brand new gun and some confidence (stay in one piece) it what you are shooting when you pull the trigger.