I practice at 200yds. all the time. I shoot an Encore 209X50 and a Savage ML ll. both of these rifles are scoped and have killed deer at 200+ yds.
This is not something that a person should do if they don't practice a lot. I shoot my ML's all year long. You must know how your rifle shoots to mark 200yd. shots. Also the wind can be a big factor at 200+ yds. Good luck.