Dale,
I know from experience you can easily dispatch moles in their tunnels with any decent firearm as they loosen up the topsoil pretty well not only letting you know where they are but making penetration much easier.
On the other hand -- watching a Jack Russell working is impressive if you can rent one because the problem with the terriers is they kill stuff like chickens, etc. You can put a gun away but a terrier must be confined.
mgg