For protection from rifle rounds like .223, .556, 7.62X39, .308, 30-06, and other long guns, you'll want to look into level III or IV hard armor plates. While these products are heavier and thicker than soft body armor, they stop vastly more powerful threats. The technology has advanced in the past few decades to make these vital products lighter, stronger, and more user friendly for the person who needs to protect themselves from high-powered rifles.
See also: What is the difference between the different ballistic panels and why the big price difference?
See also: What is a Manufacturer Ballistic Grade?
See also: What is the difference from one ballistic level to the next?