I scrounge around for cheap brass using range brass and once fired and this made me happy until I acquired a 6.5X47 Lapua and had to pay more than $1.00 each.
I carefully inspect each piece of my cheap brass then anneal each piece. Being once fired gives me the option of adjusting my loads for head space.
As you all probably know cartridge brass hardness is a function of work hardening. Brass cannot be tempered by quenching like steel. Brass cartridge heads, base, rim, primer pocket are left intentionally hard by work hardening; the neck and mouth are annealed at a later time to soften the brass allowing it to be shoved around in the loading process. I avoid 65 thousand psi loads almost always.
Generally - I think any faults are usually those introduced by the manufacturing process. My observations are best for uniformity, durability for Rifle brass Lapua, RWS (.223's), Winchester, Remington, PPU (Serbian - tie with Winchester and Remington).
My observations with Remington .45 Auto brass is that it is paper thin.
Despite its low cost I have been pleased with PPU brass - it is relatively cheap, precise, and has the right degree of hardness from head to neck mouth. I use a fair amount of it to make 6mm AI's from 7X57 (lots of estimated 61-63 thousand psi loadings). I just bought a bunch of PPU .22-.250's and am using the same loads as Winchester .22-.250 brass. I am still undecided about PMC brass and have now acquired almost 1/2 gallon of .308 PMC range and store bought once fired brass.
I never have used Brasso or any polish containing ammonia on ammo. It would appear that the amount of absorption would be factor to allow a chemical reaction at any depth but I am not about to wreak a bunch of $1.00 plus 6.5X47 cases to find out. I would need to take a look at the activity properties of copper and zinc to guess at this.
Could it be that after many cycles of compression from loading dies followed by expansion from firing work harden the brass making it more brittle and subject to splitting? ( I think - yes) Do moderate variations (less than 7-8 percent) from the usual 70 and 30 percent mixes of copper and zinc alloy mix make substantial differences in the degree of work hardening given the same degree of brass forming (I think - no). Does an increase of zinc in the mix make for harder, less ductile brass (I think - yes) Would "brown box" Lapua cases split before "blue box" cases and would they respond differently to annealing (Probably yes, despite Lapua's reputation and I don't remember seeing any "brown box" Lapua's lately)
Any metallurgists out there that could help us out? My cousin is a MIT trained metallurgist and possibly she could answer these questions provided she recovers from some anger issues with me.