I was wondering what is better a .270 or 7mm for hunting whitetails? Thanks

Both are capable for taking whitetails.For bigger game I would go with the 7mm.For longer shots the 7mm would have an edge . Both are flat shooters. Strictly for whitetails the 270 would be my choice.The 270 is my favorite deer cartridge.

Ruger Redhawk

I would tend to agree with RR, if I had to pick one I would pick the .270 for deer. However it can't hurt to own both!!

Well, first off, which 270 or 7mm are you asking about? Are we looking at the 270Win.
vs. 7mmRem.Mag, or 270WSM and 7mmWSM; 270Win. vs. 280Rem. or 7x57, etc.

If the largest game involved is going to be deer size (whitetails & mulies, etc.) then a
standard 270Win. will be all you'll need. If you may later be considering larger/tougher game such as large black bears, elk, etc., then I would look to a 7mm cartridge because of the heavier bullet loadings available (280Rem. or 7mmRem.Mag).
However, the good old 270Win. can handle just about anything in the lower 48 with the right ammo. Any advantage for the 7mm is pretty slight. Difference in bullet diameters is only .007" (.277" vs. .284").
Pick the rifle that you like, and fits you best.

Just an opinion here but for your average NA hunting short of big bears..the 270 is as damn near close to perfect as they come.

If you are hunting mostly whitetails, I would pick the .270win

only .007" difference in the 2 bullets.

Another nod for the .270 Winchester

either will work for deer, if you want to go for elk or moose the 7 mag will give you a real advantage over the 270.

I would choose the 7mm-08 over either for deer only and the 7mmremmag if bigger game is to be hunted.