12" should make a nice, handy gun. I bought five boxes of Hornady 200FP's last year. Should last me a while since I don't shoot nearly as much as I used to. I still have two boxes of the old Nosler 200 BT's. They are a little thinner skinned than the new ones and open up well at WW velocities.
I'll bet you'll be happy with your gun. It's a great deer, bear, hog caliber. I still have the original loads that were published in The Handgunner if you need any help.
Phil