On my 223 UV Handi the white box 45 JHP shoots real good. Usually under 1" at 100 yds. I finally found a handload that equals it. It is WW brass, CCI400 primers, W748 at 27.0 grains and a Sierra MK 52 grain bullet. Funny part is if you drop down 0.2 grains it opens up to about 2.0 inches, go over by 0.2 grains and it open up to about 1.6 inches. Twice now this load has shot about 1/2" 5 shot groups. Course that is my rifle, barrel, bedding, etc. So don't just give up, it has take about 250 rounds of handloads to find this load that it likes. You may just be 0.2 grain of powder off.