Bullet brand or style; a five shot group like that is worthy of keeping in my opinion.
This opinion is based on owning or have owned a DPMS 20" SS Bull, a 20 RRA Match, and DPMS Oracle.
When starting out, new to reloading and the MSR, it took me some time but I was able to produce some decent 5 shot 100 yard groups with the DPMS. I showed a couple of these targets to my friend/reloading mentor, and his comment was, "only someone who has reloaded and practiced with their AR (or any rifle) can appreciate those kind of results".