I have a model 650 with both the 22 mag and 22 LR cylinders. A few years back I picked up another stainless 22 LR cylinder, and am trying to decide where to use it. I have another 650 and a 651. I like to have the dual cylinder option and have it on several guns (like a 17 with an extra 48 cylinder), so common sense says to put it on the 651, but I think the 650 might have more value?