Running the ballistics on your 245 grain Powerbelt with a BC of .161 and sighted dead on at 100 yards, there is a 20+ inch drop at 200 yards. You hold dead on the back of a skinny little deer and you will probably gut shoot it our scare the devil out of it.

A shot like that without a lot of practice is just not practical and should not be attempted. Not that the powerbelt does not have the power at that range to dispatch a deer, but you would need shot placement at best. That takes practice.

Also out of some rifle, Powerbelts do not like to be pushed too hard. Only your rifle knows for sure, but many find that anything over 100 grains (1515 fps) and they get flyers all over the place. Now put that out at 200 yards and all you have is a mess.

If this is what you're facing, I would suggest getting some 250 grain or even 200 grain Shockwaves and working up a load with them and some pellets. I think that would give you the best chance of harvesting a deer.