I am currently in the process of having a Remington action (from a current rifle I own) restocked with a Bell and Carlson, and the leupold 4.5-14 x 40 that is on it upgraded to a turret style. I'm having this done by a gunsmith. He is also developing a load that presumably will provide up to an 800 yd capability, as this is the upper end Leupold can supply with their turret modification.
I am mainly interested in capability within the 5-700 yard range at this time. What I have been doing for about a decade is using the Remington 700, .300 win mag with the same Leupold scope mentioned above and practicing overhold. 3.5" high at 100, etc. 500 yds is still a stretcher shot, but I have taken multiple big game animals over 400yds.
I have been concerned about the parallax issue. I don't fully understand the concept, but have googled and read about it as well as had it explained. My concept so far in using the parallax adjustment is first to know the range, and then dial the knob to that setting - see if the cross hair moves on the target and then micro adjust if necessary - but I have no official practice doing this.
This last hunting season I could have had a fairly good opportunity to harvest a bull elk significantly larger than the one I did had I been capable of shooting 6-750. Not saying I would have taken the shot for sure, but I would definitely have been able to set up a couple of times for it. Very open country. Not the first time I wished I could shoot further, effectively and confidently of course.
It seems to me that the Thompson weapon, regardless of being overpriced, would serve well as a 5-700+ yard gun.
Another question... at what range should a hunter using these types of setups begin to be concerned about parallax? What range is the definite cutoff where you are a fool not to adjust for it, and under that range what consequences are there if you don't adjust? Basically, where should you have your parallax set when hunting country you expect to make a minimum of a 300 yard shot in?