[Alpo]

Pull the safety. Remove the plunger. Put the safety back in. Try it. Still stiff? Plunger wasn't the problem. Works real easy? Looks like it was the plunger/safety interface.

Look at the face of the safety. Is there a burr that might be catching on the plunger? Look at the face of the plunger. Is there a burr that might be catching on the safety?

If it turns out that it is the plunger/safety interface, and there are no burrs on either piece, I'd still do like Country suggested and work it for a while and see if it wears in.

I like a very distinct "on/off" with mine. My Kimber's safety is so easy that if I lay it in the glove box, with the safety on, just the motion of driving a few miles will take the safety off. That's not good.