I recently took a scope off a friends rifle & it had shims between the scope & the rings, I would think they should be under the mounts if they were needed at all or is there something I don't know Thanks in advance for all replys

They were in the right place. Better options out there though.

Yes, my gunsmith here in town had to shim a set of rings on my Weatherby 7 mag and I watched him put them under the ring bases.They worked just fine,no problem at all.

Shims will work in either place--inside rings or under bases--but sometimes rings misaligned enough to require shimming will be out of alignment with each other. Not always, though. It helps to have an alignment rod to check.

I recently had to shim a scope so I used the Burris signature rings with the Pos-Align offset inserts. It worked great and its so simple. It was much easier than dealing with standard shims.

thanks for the info was helpful

I apologize for a rather simple question. It's the alignment bar that you lay in the rings that shows you where to shim?

So nobody knows how to tell if things are misaligned? There has to be a tool.

Yes, they're called alignment bars. There are several makes with different features, but you can also use a 1" or 30mm pipe. You mount them just like a scope, then see where they don't fit correctly.