[DonVoigt]

The Germans eliminated the "obduration step" in the chamber(Mauser made pistols) when they went to steel ammo in WWII times.

Aluminum can be as "strong" as brass, depends on which aluminum alloy, and aluminum does not expand and stick as brass does, i.e. it expands a little less when fired and should actually be easier to extract.

Steel is as you say- hard(maybe not harder than steel in the pistol- again it "depends"), but how much are you going to shoot?
I would worry more about the plastic type "gunk" on the outside of some steel cases leaving a sticky residue.

Wolf steel 9mm has worked ok for me in a luger or two that needed really hot ammo to function.