Got this powder can in a box of other things. The can is over 1/2 full and no rust inside. The screw on top is about 5/8" in diameter.
Likely 1960-70s vintage...which means not using modern IMR4227 loading. The elder 4227 is hotter than the modern. The big question is "how hot?" Definitely not something for a novice to play with!
I would take exact small samples and burn them simultaneously and see which flares greatest. I have shot ammo that was older than I and it worked fine. If the container was kept closed the gasses may still perform.
We destroyed my uncles old powders when he passed. He had several cans of this dated 1965 if I remember correctly. He loaded millions of rounds in his life, and used to compete at Camp Perry.
I agree on the 60s or 70s. I have some old cans of powder much like those from the same time frame. Packaging was smoother in my era starting in the 80s.
A little research and here's what I found out. Might be the 60s or earlier because bar codes came out in early 70s andd were actually introduced in the mid 60s
