I will say though, with N570, expect it to be on the lower end especially if you run it hot. If I was gonna throw out a S.W.A.G., I would say 500ish rounds. A 28 nosler typically sees 800ish, this is burning 30 grains more powder but is also a .338 vs .284.
If you do a 33xc, pick your bullet before you build (I do this with pretty much any build anyway....) and do your load developement carefully and methodically. Give yourself plenty of time on range trips, a barrel cooling device and 3ish minutes between shots will help extend the life some. Then after you have your load, use the rifle for hunting, and occasionally put a couple rounds on steel at range, and you will have it for a long time. Another thing I would really strongly consider, is looking into the Bartlien mod400bb
steel barrels. They say that they increase barrel life roughly 50%, that would turn a 500 round barrel into 750. With light use, that is around 5 additional years. For 200 additional bucks on a Hammer of Thor build like your looking at, I would jump all over that. Plus, it's a bartlien, so it's gonna shoot fantastic.