What is everyone's opinion on a 40 vs. 50mm scope? Obviously a 50mm will let in more light which will be better for low light conditions but im wondering if it's worth it for the extra price. Also, I'm assuming I would need bigger rings? Does it make much difference as far as shooting it since it is sitting up a little higher off the barrel? I'm looking at a Leupold vx3 CDS 4.5x14. Thanks guys.