My Green Mtn barrel is the 15/16 version to replace the 15/16 barrel on my 50 cal T/C Hawken. The barrel is 4 inches longer than the T/C barrel, but since they are both the same across the flats... You get it, larger bore more metal removed. I'm currently at work so I will weigh the rifle tomorrow with the different barrels attached and let you know the weight difference. I bet it's not much.