You can get by with a 12" scope for the short-stock Omega if you keep it dialed inward, provide yourself with around 4" of eye relief & shoot bullets 275 grains & under.

As of today, I cannot shoot my favorite 350 grain Keith Nose or my Buffalo S.S.Bs 375 grainers with 110 grains 777 FF without getting nose-bridge cut using a 11.5" scope dialed-out 65% with 4" eye relief.

Virgin Valley offers a 6-hole base/mount that allows you to move the scope forward & install a longer one with less eye relief. They are listed under T/C Encore bases... the exact same design as the Omega. You can also buy a much thicker Sims/Pachmayer-type recoil pad to compensate.