What scope do you have now? I broke a Bushnell 2-6 trophy on my 12" 35 Rem brake'd Contender. The adjustments won't hold and it shoots all over the place too. Mine was in the Redfield 3 ring base and ring set. That barrel now has my TC 3x scope on it and it shoots fine.
I have a Bushnell Elite 2-6x on my 375 JDJ barrel, and so far, it's been fine. That scope was recommended to me by several different members who have them on JDJ's.