TrapperDave is right. I recently did this with my 223. I tried 3 types of ammo; winchester 55gr(plain white box), winchester ballistic tips 50gr, and black hills 55gr psp. the ballistic tips produced 1/2 inch groups at 100y, black hills about 3/4 inch groups, and winchester( white box ) 2 inch groups. That doesn't mean that your 223 will like the same loads. My dad and I both have rem 700, 7mm rem mag, his prefers 175gr corelokt, mine 150gr ballistic tips. I plan to try several more brands/weights etc to achieve optimum performance. Any leftover rounds are still good for plinking and ground hogs in the summer. Keep trying until you find what your gun likes.