If all you did was oil it than more than likely you put to much oil in and around the action and gummed it up. I suggest you clean it good and then only use a lite oil to wipe it down. I use Remington Rem oil but there are any number of good oils out there. I had one man tell me he uses automotive oil in his guns and a couple of others agree. I for one am going to try it myself. you also might try some Bore Butter on your action. Use it sparingly as a little bit goes a long way. I put a dab on my 700 BDL action and it really made it slick and reduced the drag.
You may have freed up some manufacturing debris when you oiled it, and it's stuck somewhere binding.,
I'd take it apart and give the action a good cleaning, then oil lightly as suggested above.
See if she frees up after that, it should operate smoothly.