What do I have?

[CC712400]

I don't trust anyone else's loads, especially not without proof that it's correctly loaded. It's very easy to be meticulously incorrect.

Pull it, dump the powder, start over with either the min. load listed for the book at the time, or pick a new powder off the shelf from modern times. Especially if the "half can" you're sitting on is 0.5lb, then the raw value of the components isn't worth the risk. It'd be a very different story if you were talking about a minimum load .38spc for use in a .357mag revolver, but from what you're saying, it could very well be that those are a max-load.

 

[a__l__a__n]

age of the round is fine but the load seems pretty light from what I can see. I'll check a few manuals tonight but seems it's usually in the 6.0 gr of bullseye for 158 grain lead rounds...

i've shot plenty of ammo a lot older than that if it's been stored and looks good.

FWIW, multiple sources recommend LSWC bullets be limited to around 950 fps unless gas checked or hard cast, due to barrel leading issues. So that explains why the charts top out at 4.5 gr Bullseye and 928 fps for this round. As far as barrel pressure is concerned, 4 gr Bullseye would be tame for a 357 magnum.