No particular problems "new" silver AA's - so far , but then again, I've only loaded about 2000 of them. Did have some problems with the new style RED "AA's ( c. 2003/4 ? ) ... These FACTORY red's were splitting on the first firing ! - 4 flats, all from the same lot, nearly a quarter would be split longitudinally - and of those that didn't, about half would split on the second or third reload. Concerned enough that I tried them in two more guns and checked the chamber/headspace dimensions. Trashed all of those hulls ... and subsequent ammo from the the following years revealed no issues.
I still have a couple of 45 gallon drums of once-fired "old-style" AA's, in 12 & 20, that should hold me for a while yet, as well as maybe 5 or 6 thousand Federal GM's which load-up very well with "Federal" type wads (for the straight-walled hulls) The few hundred RST's I played with so far seem, by far, to be the best hull there is these days -an opinion shared by many ... I just hope Remington doesn't follow in Winchester's foot- steps to screw-up their product.