What is the most commen Cartridge used for Deer in a T/C Pistol?
From what I have read on this sight 7-30 seems to be TopDog .
As a few have posted, IMHO, the 7-30 is about the best deer "factory" cambering available. Custom Shop wise, I would look at a 30-30 AI. It will outperform the 7-30 hands down.
Assuming you are talking about the Contender, if you are asking about all T/C's, I would look at the 7mm08 or 308. Mild recoil and great all around cartridges for deer.
BUT, my next question is what type of shooting will you be doing? Under 100 yards, I would say go with the 375 Win or 44 Mag! Particularly if you are going to be handgun hunting out of your bow stand or shooting around heavy brush.