Depending on a ton of variables, if you use the proper long range load for that caliber, you will need an estimated 38MOA to get to 1200 yards. The scope has 45 MOA. A rough guide is that a zero cant base with a low mounted scope takes away about 10 MOA from your centered reticle, in this case 22.5 MOA up and down from center. So with a canted (20 MOA base), you might get 32-33 MOA while still retaining the ability for a 100 yard zero (which may not be important to you). So I'm betting you will run out of adjustment, especially considering that you will likely not be dead nuts centered on windage out of the box.
It's a good scope, but not made for 1200 yards with that 1-inch tube.
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