with my 220. Mounts slide to the end of the receiver and were dinged up pretty good. If those are the factory mounts chuck em in the trash and get the high profile accushot, inexpensive and comes with a stop pin.
Here is the site........
http://www.pyramydair.com/cgi-bin/accessory.pl?accessory_id=635
If ya dont wanna go that route, I used gorilla glue. Stayed on even after taking a hammer to the mounts, end result, new mounts and a mess to clean up. Really frustrating when trying to get it zeroed in. Get ya some good mounts for that great scope, you'll enjoy it.
Matt