How did you pick 1500 yards as the goal? Do you have steel to 1500? Not being an ass, but have you ever viewed results of KO2M results? A lot of guys with cheytac size cases fail to advance at 1500, which is around the starting distance. Their target size is generous too.
Any cartridge that stands a 60% chance of a first rd impact at 1500 and the words good barrel life don't belong together.
That said, one day in 21mph winds full value from 3 o'clock, I went 5 for 5 on a IPSC at 1500 with a 6 dasher. But I had warmed up at 1350 & 1450. If I had started there, well, you can guess.
I am about to take possession of a 25 saum, and I really think it will be a fun rd. But I bought 1500 bullets for it and bet I have at least 300 left over when the barrel gets pulled.
If it is windy and the plan is to shoot past 1200, I bring a 7 saum, usually does the job. After 10yrs of shooting one, or 2 at the same time, many barrels, I am going bigger. May be tough choice, I am not a 300 WM fan.