I am putting a scope on an older Browning and ran into a problem tonight. I have a one piece Browning base that is now firmly affixed to the rifle. Tonight I got a set of standard mount Leupold rings. I dropped the front ring into the hole in the base and I can turn it 360 degrees with my fingers without much resistance. I can just barely feel a very small bit of slop when it is lined up the way it would be with a scope mounted. I know that this is supposed to be an interference fit that requires a wrench to turn the front ring in. Before I grab a ball peen hammer and start trying to tighten up the fit, what is the correct way to address this problem? I thought all standard mounts should work with any ring made for a standard base. What do I do?

If the base was in a "Browning" box, I believe they were made by Redfield. Leupold and Redfield are sometimes not a perfect fit, though LOOK the same

Yes the base was a Browning branded part.
Are you saying that I should look for some Redfield rings?

A mentor told me years ago that Redfield mounts are not hardened and freguent scope removal can result in loose fit as you describe. I would replace the base to match the rings or try Redfields rings. I have fixed loose fits with a 6-48 set screw d&t through side of the base to bear on the dovetail, works if nothing else is practical.

Well, I guess it's off to the gunshop to get a set of Redfield rings. I am not planning on changing rings or scopes often on this rifle so that shouldn't be a problem and it's a 257 Roberts so it's not a high recoil application.