Your post is somewhat ambiguous, are you asking if a 6.5 grendel is a good cartridge for a beginner and or if that particular bullet is a good choice? Almost any centerfire cartridge will do quite nicely at 200yds. A 6.5 grendel is a somewhat unusual choice for a 1st choice but is a very capable cartridge for what it is. What are your goals? What is "best" is a very subjective question without more information.