Correctomundo, re: mercuric primers being death to fired brass. Moot point though, as mercuric primers started to be phased out at the turn of the century. The 20th century. All gov't .30-06 ammo was loaded with non-mercuric primers (but very corrosive nonetheless) from day one. All ammo loaded prior to that (.3040 Krag, .45-70, etc.) must be considered to be mercuric, but who's shooting that stuff anymore? (Actually, I did. As a kid and young adult in the 60's-early 70's we shot up boatloads of that stuff in our Krags because it was dirt cheap. Left the brass in the garbage and went home and dutifully cleaned the guns- no harm, no foul. It seemed back then every gun show table had piles of the stuff for around $3-4/100.)
The old Frankford Arsenal FA-70 primer, the notorious "corrosive" primer, was developed well before WWII and was spec'ed by the gov't for all .30 ammo produced by private contractors. It was a wonderful primer- able to not degrade under extreme conditions of storage/use and with very very consistent ignition properties. The Ordinance folks at the time were well aware of the advances in primer technology in terms of non-corrosiveness, on the part of our commercial producers and foreign entities, but decided to stick with the old FA priming compound because of those traits. They figured that the trade-off was worth it and were willing to accept the necessary protocols of religiously cleaning weapons after use.
When non-corrosive compounds got to the point where the FA primer became moot, the phase out began. There's no way to pin down exact dates and lot numbers of ammo from private contractors that are categorically non-corrosive, but it's still a rather narrow time band. It's pretty safe to say that 1953 and later headstamped stuff is safe, and absolutely post 1954-55.
As stated earlier, brass fired with corrosive primers is perfectly safe for re-use. Wash it out if you feel the need but it's not necessary.
Wartime brass has other issues which may or may not effect a modern handloader. While it is generally excellent brass and made under strict QC oversight for uniformity, there was a war on after all and in the rush to get the ammo out the door and into the hands of the boys overseas sometimes stuff got through that shouldn't have.
