Follow-up report: Before I went to the range I pulled the bullet on one of the 250 Savage rounds loaded in 1999 with the suspect lot of VV-140 powder, but in Winchester cases.
There was not the slightest hint of corrosion inside of the case or on the base of the bullet. The powder looked perfect.
At the range the remaining rounds of both boxes performed perfectly and the velocities through the chronograph were within expectations.
These results suggest that my problems with the Federal 30-30 cases are more related to the cases then to that lot of powder.
As Denton reported, it is possible that moisture inside the case could cause corrosion like that, but I don't know how it could have happened. And the 30-30 rounds and these 250 Savage rounds have been stored together in the same conditions since 1999. The corrosion problem has never happened to me before and all my loading procedures have always been careful and consistent with normal results. I guess I am going to blame the problem on bad brass.
