I have a TVM Fowler and thinking about adding a rear sight. I bought one from TOW and lashed it on with some small leather cord and it has definitely helped my groups. I've tried it at different locations and at my age,58,it's clearest father down the barrel right where the octagon portion ends. My question is,what effect does it have on shooting with the sight that much farther from its normal location? By the way,it's a 42 inch barrel.