Agree with IKE, you need to find the right balance of magnification and holdover/elevation, otherwise you may end up with an unfavourable combination.
I usually only shoot up to 1,500 meters, but recently shot a mile in Hungary and had to turn down the magnification to about 34x to be able to see enough hashmarks for a 4 mil holdover (with clicked elevation 17,2 mils on the March for a total of 21,2 mils -note: this is a .338 Lapua Magnum in which I'm running a relatively hot ammo). On my old Savage 110BA topped first with Premier 5-25x and then S&B 5-25x I could click all the way for a mile and use maximum magnification (unless the mirage was really bad), however lower-cost riflescopes usually don't have as much elevation available as these top dogs. As an extreme example, when I was shooting with .308Win at 1,500 meters I had to use maximum elevation on the Premier with 40moa sloped base and still had to dial down to only 8x power to be able to use the hashmark all the way down on the thick stadia line of the reticle for holdover...
Anyway, what you also need to consider is that usually you want to zero your scope at about a third of the way down of the elevation (if you use a lot of slope/angle in your mounts/base and zero your scope all the way at the bottom, it does give you the full elevation range as specified by the manufacturer of the scope, however you lose a lot of optic clarity, you gain the 'moon circle', your parallax adjustment for close range - hundred to couple hundred meters - will be quite poor, and many scopes also tend to have slightly differing clicks at the extremes of scope adjustment (all the way down and all the way up, they are usually a bit shorter - i.e. 0.1 mil in the normal adjustments, but only 0.095-0.09 mil at the extremes). Same also goes for the opposite extreme - when you click all the way up to maximum elevation, your sight picture often starts to deteriorate, your clicks might not be absolutely exact (which at these distances makes quite a difference), so you may want to dial down a bit and then rather use more holdover (dial down to the 'small mils' and then use full mils for holdover - in my example above, my March FX has 24mils/66moa theoretical elevation available, but with A.I. AX338's 30moa angled rail (and no additional angle in scope mount) zeroed for 100 meters I could practically dial 18 mils of useful elevation, for a mile on that day I needed 21,2 mils elevation, so I dialled 17,2 mils and used 4 mil holdover (this way you aim with a 'cross' of reticle hashmarks).
Bottom line - check your ballistics - how much elevation will you need with your 338 Norma Mag load to get to a mile (up to 1k its similar to 338LM, but over 1k the slight difference starts to show), then check whether the scope will have enough travel - what elevation you will have available will depend on how much moa-angled base/mounts you will use and whether you will zero at 100 or more. On paper the Leupy you are considering should have just enough elevation, but after mounting/zeroing you may end up with only 50 or even less moa available, and you will need quite a bit of holdover. In this case FFP really helps to avoid all the re-calculations with magnification changes, but if you have to go down too much with the magnification you won't be able to be very accurate. Since holdovers are in general not very good for accuracy (which you will need for one mile shots), if you plan on shooting a mile accurately or often, you might want to consider something with 120moa or more (theoretical) elevation. Above mentioned ATACR and Vortex Razor both fulfill this criteria, but you lose FFP, so instead you perhaps could consider second-hand S&B, Premier, or other top optics (for these distances you really need top quality optics, and you would probably end up getting one of the 'big boys' eventually anyway).
Good luck and safe shooting!
Gunslinger
P.S.: Sorry for the longer post, here's a pic of the shooting mentioned above:
