A lot of very good and informative information in here.
And so, the cheap~O~BSA that I would be afraid to spend twenty ti fourty bucks on, could actually be a good entry level sight, before moving on to the bigger, better, faster and more sighting systems.
Six hundred yards, that is mighty impressive, especially the telling of the adverse weather conditions. Wind chill involed would be between -8 and -35* F. I must say, You have a lot more desire to be in the cold than I. The front axle actuator on My pickup burned out, it is 9* out, I am not willing to even open the garage door to get the pickup in to change that, let alone lay out in a snow bank to get the job done, warmer days a coming. I must say though, that I admire Your endurance and spirit for being out there in the cold.
Next problem. a bunch of years back, I charged up some credit cards, have been really living on a very low budget, but, 2 of them cards is paid offt, about 2,000 on two others, one of which is within about 150 bucks, it will be paid offt this month, Christmas is going to be mighty slim, The wifey will get nothing for Me, I will get nothing for the wifey, the childrens will get nothing, the grandchildrens will each get a crisp 20 dollar bill to do with whatever they would want.
I will not make any purchases unless I talk it over with the wifey first to make a decision to or not to purchase, She came on board while I was first trying to get debt free, and every dollar spent to make a purchase online, is another couple of bucks from getting the cards paid offt, and so, to be able to make the purchase, or to want to, may take some soul searching, even for less than thirty bucks.
I`m a working on it.