Thanks for the added info. Here is my view of the 338 LM at 1500 yard hunting. With a 28" tube and muzzle velocity of 2800 or so with a 300 gr bullet the 1500 mark is kind of a place where the numbers come together.
1500 yards, impact velocity of close to 1500 fps and energy matching close to 1500 lbs. Will this do the trick? you bet. But I worry about the capabilities of the factory rifle and I sure would rather have hand loads with 300 gr bullets. I myself would only use a 300 gr Berger here. Not all rifles are created equal. That goes for factory or customs. I feel you will need a combination (rifle, ammo, shooter skill) that will repeatedly hold 1/2 moa past 1000 yards to effectively take on this feat. If a factory combo will do this then I say you have a darn good one.
Also, lets not forget the very important element of a correct and spot on range of the intended target. The number of rangefinders I would use for this is limited. And for sure they are not cheap. I would look at the size of the beam that the intended unit has at 1500 yards before I trusted it. Many units will be casting a 9 foot plus beam. That makes a mis range very easy and a 10 or 15 yard mis-range of on a closer more reflective target will be a huge problem for a cold bore hit where you want it.
I won't go into what it will take for a good scope, but I sure would be looking for at least 22X and plenty of elevation as 50 moa up could be needed.
So, with a drop in velocity of the 26" tube, loss of energy of a 250gr bullet over a 300 gr bullet and loss of BC added with the chances of a factory combination probably not holding 1/2 moa at these distances, I think you are up against a challenge with the equipment you listed. Now 1000 or 1200 in good conditions are looking a lot better.
You asked about barrel life. My 338 LM is still holding 1/2 moa after close to 1500 rounds. So that is not an issue with either the 338 EDGE or the 338LM. But as you step it up to larger cases plan on the number of rounds before rebarrel beeing less as velocity goes up. I used my 338 LM to train and hunt for years and now I am stepping up with a new chambering and rifle design so I will be more prepared for a shot like this. If and when the stars align and conditions are there. So I feel the EDGE or LM are a great choice to get you ready. Then once you know what it takes and feel you are there would be the time to step up to a larger case as you will not be beating up the barrel for all the practice.
I've bumped my scope before too.
I went shooting with these guys repeatedly and it was always the same, with different rifles. Even with my rifles.
Was fresh in my mind cuz' I did it last weekend (not scope but turrents). On top of that I grabbed the wrong dope sheet. My brother and I had been talking smack about who was going to kill the most prairie dogs. Neither one of us could hit anything. My 12 yr old son did all the killing, took him out cat fishing that night and he caught all the fish as well. He's been informed he's not allowed to go with us anymore.
Glad to hear you gave them a second chance. If there not hitting on time 2 let the shame begin. The more smack talk the better. This will help as either there won't be a 3rd time or there will be a vast improvement in their shooting the next time.
Buster, I'd stick with the .308 this year. Better decisions are made when not under the gun. Your already proven and comfortable on your current rifle. No sense in rushing yourself.
This is the decision I made. I have been shooting a 300 RUM for 3 years now getting comfortable at longer ranges and better in my reloading. I've spent a great deal of time and money on becoming competent at longer ranges. Now that I can hit 1k very reliably I am building a 338 lapua improved. I'm mainly building this rifle for a bear hunt that I plan on going on in a few years. Yes, I said years! I only get to shoot a lot during the winter so, for me, it will take a few years for me to become comfortable with the gun and load. I plan on taking this gun to 2000 yards and I know it won't happen right away. I haven't been at this nearly as long as these other guys, but I, too, would suggest waiting. Save up and buy/build exactly what you want with the optics (rifle scope, binoculars, rangefinder) that you want. I have been saving for my 338 for a year and a half and still don't have a scope bought yet and I will keep saving for a vectronix terrapin. A lot of people don't think of things like a $2000 rangefinder that will reliably range to 1500 yards. Do what you want, but if I were you I would wait until next year when you won't have to rush.