I've got a rifle that has 1" dual dovetail bases/rings on it now and I'm pondering swapping the scope out to a 30mil. When I change rings, can I use the existing bases? Or should I swap out both new rings and new bases? I've heard that the rings and bases gall together when you twist them into place and form a mating surface that only securely holds once. Any truth to that?

I've re-used the bases multiple times. If necessary, flip the base over, and rap the underside with a punch to restore the tension.

Most quality d-d rings have some anti seize either in the package or already applied to the dovetails (a waxy coating) to prevent galling. Using that, I've never galled either the rings or bases.

With a dab of anti seize, if they're tight when they go back on you should be fine. If the mating surfaces are scored and thrashed, I'd replace them, even if they're tight. Before rotating the rings off, squirt a bit of Kroil or Marvel Mystery Oil around the dovetails and let it sit for a day. If they were installed w/o any anti seize, this helps keeps the scoring to a minimum when they come off.

Works for me. -Al

A few years ago I bought new DD for a Weatherby (2 sets mine and a buddy) MKv. I have used them for years and never had issues reusing. That changed on these two sets, I wasn’t changing them but installing and aligning them. They were loose and wobbled after they were aligned. Leupold did replace both sets and I installed one set on another rifle. No problem with the replacement. Best to lightly lubricate during install.
I ended up going with a Near Mfg mount for the Weatherby’s

I don't re-use if I have to change or adjust rings. I usually keep the B&R if I sell a rifle w/o scope and if everything remains lined up when I stick the B&R on a new action, I have no qualms about using them, but I had one base get slightly boogered .. too subtlely to tell visually .. which lead to accuracy problems and wasting a bunch o' components before realizing what the problem was. (Credit goes to a gunsmith friend who asked if I'd re-used the bases.) Once I swapped in all new stuff, accuracy problems vanished. To me it's not worthwhile. Dual dovetail bases are .. what, maybe $20? False economy.

Right, not worth the expense. But the issue is, I have the rings and the scope in hand now, from what I had laying around. I'd need to order the new bases and didn't want to wait, but I suppose I should. Thanks all.

They can gall. I always use gun grease to avoid that. You can definitely re-use them. Guys that gall them up don't know what they are doing... Use grease.

Another trick you can do if you re-use a set is this:

Mount bases onto rifle action, twist ring dovetails into bases to align. Once you have mounted and bore-sighted rifle satisfactorily, unscrew top half of rings and take scope out of rings. Take bases(bottom half of rings still twisted into bases)off rifle being careful to note direction bases were installed on rifle.

Degrease the underside of base(hole with the ring dovetail screwed into it). Once degreased well(I use rubbing alcohol and then heat up well with hair dryer to make sure all moisture has evaporated) and thoroughly dried, fill the underside of the base hole with acraglas bedding epoxy being careful not to overfill and disrupt the contour of the underside of the base. Once epoxy is cured(overnight), reinstall bases in same direction they were previously positioned on the rifle.

Obviously, once you’ve done this you have a permanently fused together ring/base set. I’ve done this several times on rifles and never had problems maintaining zero…..it’s better than throwing a previously used set of dual dovetail mounts away.

Leftybolt