Roger,
Sounds like you have figured out what a lot of us aging bowhunters are having to admit - those crossbows aren't really so bad after all!
As for the old powder, I'd not trust the results using it.You might want to get some new triple se7en and give it a try. I just bought a pound of it and so far it has been the most consistant modern"replica" powder I've tried. (I'm not including Pyrodex in that classification of modern, Pyrodex is a very good powder) I still like regular old Goex BP for testing the accuracy potential of a gun, though. It's a bit harder to clean up after, but it has usually provided the best accuracy. With inlines I often use Pyrodex instead of BP to check accuracy potential. It's a bit easier to clean up after, and accuracy is very similar to BP in all the inlines I've compared it in.