There are several schools of though as far as long range shooting and hunting goes.
There are those that think anything over 200 yards is long range, which is perfectly fine, in most instances a good hunter can get within 200 yards for a shot. For this group of hunters, even a 30-06 has a laser flat trajectory over that distance with nothing at all needed in hold adjustment at all. Just point and shoot.
The next group of hunters believe that the outer limits of practicality fall in the +400 to 500 yard range for shots on game. Again, the vast majority of factory rounds will perform well out far enough to cover most of this range without excessive hold over. Rounds like the 7mm Rem Mag and the like are gret for this type of shooting.
These hunters still want to zero their rifles in at 250 or so yards and for anything longer they will just apply the right amount of hold over.
Problem is that at ranges around 500 yards this becomes a guessing game with hold over amounts and bad things can happen quickly.
The last group of hunters, the ones that are on this post are a different breed of cat, I like to think I am one of these hunter. While we do not require an 800 yard shot on big game, we practice, research and build rifles and use equipment that make shots at these ranges and farther relatively easy, not just possible.
At these ranges, no matter the round or rifle you are using, "holding over" simply does not work. There is to much error for making accurate hits using this method.
The best way to accomplish hits at extreme range is to use a ranging system consisting of an accurate laser range finder capable of consistantly measuring the max range you will be shooting at, an optical system that will be consistant, accurate and repeatable in adjustments, and finally a rifle and ammo combo capable of extreme accuracy at long range.
From reading your posts, I would place you in the middle group of hunters which there is nothing at all wrong with any of them.
What I would recommend for you is to get a scope with reference marks on at least the bottom half of the vertical stadia of the reticle. I prefer the mil-dot system as the dots are evenly spaced and easy to figure out a drop chart for.
For those not wanting to dial in adjustment for every shot, and if you will only be shooting out to 800 yards or so at max, you can develope a load and then develope a drop chart that corresponds to the reference points on your reticle.
Once the drop chart is range tested and tweaked until it is accurate, it can be suprizing how fast and accurately you can place shots at varying ranges from 0 to 1000 yards depending on the rifle set up.
For instance say you have your 338 RUM loaded with the 250 gr pills at 2850 fps and zeroed at 200 yards. Well you see big daddy bull elk across a canyon. You pull out your range finder which shows the bull is 480 yards across the canyon.
You look up the range on the chart you have with you, either taped on the rifle somewhere or as a loose chart. The 480 yard range would refer you to which reference point to hold on and where the bullet will impact + or - the reference point. Also, it is nice to have a wind drift measurement as well, I like a 5 mph and 10 mph number for each range, anything higher then that I will not shoot and even in a 10 mph wind I will generally not take a shot.
Anyway, you settle in for the shot, find the correct refference point and let the shot go with an accurate holding point which will make your shots much more consistant and accurate.
The best thing is that when your walking back to camp and you jump that monster mule deer buck at 75 yards, you simply pull up and shoot him using your main crosshair.
This system can take considerable range testing especially if an accurate B.C. is not available for the bullet you are using. But once set up correctly, it is a simple matter to hit targets from point blank to well past the half mile marker.
Now for percision shooting at extreme ranges, nothing compares to dialing in the correct adjustment and holding dead on for the shot.
Still for many hunting situations, espeically at 600 yards and less, I prefer this other method and it has worked very well.
This pic shows a 30" barreled 6mm-284 built to shoot the 107 gr SMKs and does so at 3550 fps.
During the summer of 2003, I tested this rifle using the exact drop chart system discribed above except that it was adjusted to work from a minimum of 400 yards to a max of 1100 yards using the entire vertical stadia of the mil dot reticle.
That summer, this rifle scored one shot kills at 515 yards, 523 yards, 713 yards, 714 yards, 868 yards, 903 yards, 955 yards and finally at this 1055 yard. Now I am not saying this system is full proof. Many ranges will fall halfway between a pair of reference dots and this is when you really need to know where the bullet will land + or - the hold of the reference point being used.
I also tested this system on a set of 12, one gallon milk jugs filled with water set out at ranges from 540 yards to 980 yards, everything else being in between these ranges.
Shooting off a harris bipod in front and a small field bag in the rear, I scored 11 for 12 hits. The miss at about 860 yards and I was not paying attention to the wind on the shot and the bullet landed about 10" wide to the left.
Point is with a properly set up drop chart, your 338 RUM, if the rifle us up to it, and you can shoot it well enough, is capable of hitting targets at ranges well past 600 yards with no scope adjustment at all if you use a drop chart system with a mil dot scope.
The singlel best scope I have found for this type of set up for big game hunting is the Weaver Tactical 4.5-14 with the mild-dot system. This scope, unlike most scopes has the reticel on the first focal point so the mil dot spacing stays consistant with the target over the entire power range of the scope. Something extremely useful for the big game hunter so you are not tied into one set power that your drop chart is calibrated to.
So for 300 yard shooting, you really do not need to worry about hold over much with the big 338. Probably not off hair anyway on game the size of deer.
For longer range shots, the system I mentioned will offer you +600 yard capability, again if your gear is up to the challange. It will also do this with a fixed scope setting as well.
Again for extreme range shooting, there is no substitute for dialing in your adjustments on fine equipment.