An O crony in Department of Defense DID reclassify used brass so that anyone who bought it was required to shred it.
That lasted about a week. There was an
attempt to reclassify D.O.D. surplus brass such that it would be destroyed rather than eligible for resale to ammunition remanufacturers. The attempt was shut down so rapidly by efforts from pro-gun organizations (primarily the NRA) that no brass was actually destroyed.
Therefore
there was no practical impact on the shortage situation as a result of this attempt other than perhaps to induce some panic.
I have not seen any evidence linking the attempted reclassification to any "O crony" although I suppose it's possible.
Back in 2007 OSHA did make some noises about reclassifying primers as explosives but that never even got past the proposal stage. Again,
it contributed absolutely nothing in terms of causing any shortages other than, again, to possibly induce some panic.
This clearly had nothing to do with Obama since it happened long before he was elected.
The bottom line is that NO ammunition components have been reclassified in actual practice. In one case there was an attempt to reclassify military surplus brass that was shut down before it could have any effect and in the second case it was just a proposal--they never even actually tried to reclassify the primers.
The ammunition/component shortages are due to combinations of the following things:
1. Two wars resulting in large military ammunition orders.
2. Reduction of ammunition imports for various reasons.
3. Panic due to the election of an anti-gun president.
4. More panic due to people seeing that there was a shortage.
5.
Even more panic due to people circulating apocryphal stories about how anti-gunners in the administration are somehow restricting supply to the civilian market.