HSM Ammunition Starline Rifle Brass Unprimed Cases Win Caliber 50 Per Bag. 38-55 is the standard length of 2.080" which is the same as Winchester case. Case mouth has thinner walls (.0072" average thickness at mouth) than the Winchester case allowing for use of the wide variety of bullet diameters especially in tight chamber/large bore situations. Specifications for Starline Brass Unprimed Cases 38-55 Win Rifle Brass: Manufacturer: HSM Ammunition Gun Type: Rifle Caliber: .38-55 Winchester Primed: No Quantity: 50 Fabric/Material: Brass Package Contents: Starline Brass Unprimed Cases 38-55 Win Rifle Brass