Danny, there is no exact answer but there are a lot of things you can do to hasten or shorten your cases life. First, let's assume allyour rifles have good, properly spec'd chambers...otherwise that can mess up the equation right out of the gate.

Assuming this, the worst thing you can do for the life of your brass is fire maximum, high pressure loads. This can render brass unsafe of even unfit for use with one firing. Backing off on your loads 2-3 grains can make a big difference in case life. For some reasons magnum brass is terrible about primer pockets swelling. The rest of the case may be fine but after 1 or 2 reloadings, the primer falls out as fast as you stick it in...with your fingers, I might add. Obvious this brass is now garbage. Annealing the cases won't help you a bit down there.

I do a modified full length resize on all my rifle brass all the time and never play with the anneal game. I do shoot closer to "suggested loads" than near the maximum and all my brass goes around 5 or 6 times without showing signs of stress. 243 included.

I don't think you'll do quiteas good with 30/30 as BC speculates. It's lower pressure alright but 30/30 is also about the thinnest rifle brass out there. The 30/30 case is just basically a weak sister and was...keep in mind...actually designed for black powder.

Bottom line is how long your brass lasts will depend on how you treat it and load it. Magnum cases look big and tough but they are not. Things like 308 and 30/06 brass will often last until you get sick of looking at it.