The less you "work" the brass through full length resizing, etc...the longer they'll last. If you see any signs of cracking around the mouth or any bulges, etc...around the base its time to chuck it. You might want to keep an eye on your primer pocket as well. Some brass, with a steady diet of hot, "full-house" loads can see the primer pocket stretch causing seating problems for your primers.
How long your brass lasts, is also very dependent on the actual cartridge you're shooting and your particular rifle. For instance, I can get 20-30 reloads out of good quality .45ACP brass, however, .303 British case length is maybe 4-5 reloads because I fire it in different rifles with varying degrees of "generous" chamber dimensions. (headspace is okay in all of 'em) I've gotten more out of some, but it also depends on how meticulous you want to be. Stick with one lot of brass for one particular rifle, neck size that same brass instead of full length resizing and it can last you for years.
Straightwall pistol brass usually lasts quite a while anyway, with some exceptions, like .38 Super. However, you shouldn't have too much problems with your .44 Mag brass in that Raging Bull of yours!