This is a Ruger Revolver: Double Action known as the GP100 chambered in 357, model # 1783, UPC 736676017836
Model Series: GP100
Gun Type: Revolver: Double Action
Caliber: 357
Action: Double Action
Capacity: 6
Finish: Blue
Sights: Front: QC Rear: Adjustable
Barrel Length: 4.2 Shroud Barrel
Overall Length: 9.5
Features: Custom Engraved Barrel
