Best factory 7mm cartridge for whitetail?

[Purebred Redneck]

All I've ever shot in my savage has been super x (with one exception - once I tried remington controled recoil and ended up with 3inch groups at 50 yards).
I get around 1 1/2 - 2 inch groups with them at 100 - which is plenty accurate for up to 300 yards on a deer sized animal.
I'm sure they would shoot better if I had a decent scope and rings on the gun.
I pay around $17 for them.

You can get winchester ballistic tips (I believe they are called supremes). But they go for like 25 a box.

If you are shooting primarily for deer hunting, there is no reason to use anything but the cheapest shells - either corelocks (which I hate remington ammo with a passion burning deep) and Winchester Super X.

If I were doing what you plan to do, I'd try 140grain(I think it's really weird like 139gr), 150, or 170 superx.
Actually, I'd just get the 150 and never look back...

You're only shooting 200 yards - the biggest factor with that is going to be your rest.