With these parameters in mind, you have lots of choices. Actually, one option is to do what I do and get yourself a bullet for hunting and a bullet for target shooting. For example, in my .30-06, I've found that the 165 Nosler Ballistic Tip and 168 Barnes TTSX shoot to basically the same point of impact at least out to 400 yards when fed the same charge of powder. I don't believe there is an animal in North America that is safe from a 168 TTSX out of a .30-06 at ranges out to 400 yards, as long as the shooter can place the shot consistently. For cheaper shooting on paper, the Ballistic Tip is perfect and accurate.
However, I am not sure about your plan to shoot long ranges without dialing your scope. No matter how you slice it, after 300 yard (and even AT 300 yards), you are going to have to adjust elevation, and dope the wind. These days, I've settled on scopes with graduated hash marks or dots, and they work really well, once you get the hang of them. With older scopes, it's possible too to shoot without dialing the elevation. However, to do this, you have to calculate the reticle subtension at the highest power (i.e. the distance from center to the top of the bottom post) and then twist the power accordingly to use the bottom post at the specified range. Here is an example: at 9 power, if you have 3 minutes from center to post, that will give you 6 minutes at 4-1/2 power and 9 minutes at 3 power. I know that with my current zero on my Mauser, if I leave the scope at 9 power, I can use the post at about 350 yards. At 550 yards, I just have to crank down to 3 power and use the post -- all with the same load. I've done it a few times, and it works.
Bottom line, for long range shooting, you will need a fairly precise and repeatable way to put the elevation on your rifle if you hope to hit anything consistently. Once you accept that premise, any reasonably accurate load will work. In the Mauser example I gave above, I'm shooting a plain Hornady 180-grain flat base SP at 2,640 f.p.s., using an ancient 3-9 Redfield scope, and it hits consistently and predictably out to 660 yards, which is as far as I've played with it so far.
Therefore, my first recommendation would be to find a decent load that works and try shooting it at longer ranges, ideally with a scope that has hash marks or dots. The rest will follow in due course.
. I initially went with the 180 because I plan on going bison hunting someday and the regulations are a min .30 cal with a bullet weight of 180gr for bison. I've been considering going to a 165-168gr bullet in the 06 for hunting since I picked up a 9.3x57 that I want to try on a bison. I usually keep my target shooting and my hunting loads seperate.
