All About Pocket Knives

I have a 1985 Sodbuster Jr. I bought at a flea market for $12. It's in great shape and I'd like to EDC it. The problem is that it's a little hard to open, it is extremely tight and it's makes my thumbnail sore. Is there a way to be able to make it open easier? ftd

A little oil on the joint will help some, but it seems all of the Sodbuster Jrs that I have handle are a little tough to open.