These are some interesting ideas.

Cayugad: I picked up a rubber mallet last night at Home Depot and will give that a try.

Lonewolf: would you please post those pics. I would be interested in seeing them as well.

Lemoyne: I would have thought moisture as well. However I live in Phoenix, Arizona. Any drier and I'm likely to turn into beef jerky.

When I next pull the lock for cleaning, I will look for any high spots.

Sabotloader: who knows, maybe I just got lucky and got an extra tight fitting stock. Or like Lemoyne suggests, a lock with a high spot or two.

Thanks again guys.
~Robert