The B14 and the HMR Pro are two different rifles. The HMR Pro is built on the Premier series action among other upgrades like stainless , Triggertech Primary trigger. The B14 is their basic action and stock trigger with carbon steel barrel.
Are you specifically looking for used? I was asking an FFL to check on some guns for me a week or two ago and he said the B14 was out of stock but the HMR pro was available. Maybe check with an FFL?
Edit: In .308. I think he uses Sports South and Davidson as distributors.
I just shoot for fun me and some buddies steel and paper mostly. They all got b14 hmr wilderness the rifle feels really good. Just trying to see what the pro is about. We are all grew up hunting deer with cheap savages and remingtons. We are just now getting our feet wet in long range.