ChuckS1 gives the old standby .38 target load and it is as good as ever - if you are a careful handloader.

In my experience, Bullseye has been very consistent as long as I have been using it - way more so than Unique and #2400. (Don't know all that much about Blue Dot.) I would make a few test loads and try your Bullseye - as long as you can positively identify it and there is no tell-tale rancid odor to it.

I still use some rather old powders that were "before Alliant" and have good results with them. Success in doing that mainly seems to depend on storage. If left in the original container and stored at reasonably steady temperatures around normal room temperature, I have noticed no problems.

If you have any serious doubts, pour it out and burn it up. A can of powder is not worth risking destroying a gun - and maybe hurting someone.