re: Gun question...

My .444 will shoot sub MOA groups at 150 yards. That said, I've never shot it at a deer that far. But I would if I had to. here is link to ballistic chart I use for it. LINK

I'm not real sure how that link will work for you, but I used the ballistic coefficient from Hornady lever revolution ammo (.225) bullet weight 265, caliber .444, Muzzle Velocity 2325, sight height of 1.8125 (yours may be different), zero range of 150, temp of 59 and pressure of 29.92 ( I think that was default), I set it at no wind.

Any way, my chart says if zeroed at 150, it'll be 4.2" low at 200, and 11.7" low at 250.

As far as would it kill a deer at what range? Who knows. There are all kinds of arguments on how much energy/bullet speed is needed to kill a deer. Farthest I've killed a deer (240 lbs) with the .444 is 100 yards. I killed a coyote at 150. Both never took a step after the 265 gr made impact.