I have a few Tikka rifles that I want to swap the rings out on, but none of my tool sets has a bit or tip to fit the factory screw heads. My allen wrench sets to not fit either. Anybody know what tool fits it, so I can go buy one?

Do you have a 3mm Allen?

I think all my Allens are SI units. So I need to go get a metric set of allen wrenches...