Being stored in a south (actually Central) Georgia barn at 100-120° for many summers and 35°for many winters would probably play havoc with all components especially powder, primers and brass. Just my thoughts.I ran into a similar problem with .243 ammo, which was reloaded by my dad and stored in a Pennsylvania basement 20 years or so earlier. Read about chemical welding of case mouth and copper jacket. When I went back and re-seated the bullets by a thousandth or so, I noticed that several of them felt like they "broke loose" during re-seating. No pressure problems after that. Of course these were 20-25 years old, not 12. But, worth a try?