The brass gets harder and stronger after each firing. Untill it cracks.
With my 44mag I have used up to 33gr of H110 with 180gr XTP. But I don't use magnum primers. And yes that is a hot load. (May not be safe in all guns.)
I have loaded 30 and up to 33gr H110 powered 44mags up to 3 and 4 times. I haven't been able to shoot my 44mag as much as I would like or else I would have reloaded them more.
My plinking load is 44mag shells, 180gr XTP with 10 gr or unique. That is a real light 180gr bullet charge it also makes good a 240gr cast bullet charge.
I use 10gr of unique for safety, it fills the case half way up.
The funny thing is some factory rounds just start to show signs of high pressure some times, and my hot loads don't. Strange.