Let's be honest, most 450 bushmaster game animals are shot at less than 225 yards.
Why not load the barnes MZ line?250 and 300 grain even the 225 grain xpb for pistols. Those bucketmouth copper mothers are itching for a on whitetail launch from an AR. I use these in a savage smokeless mz at similar velocity and they are devastating the long for weight, stiff copper should help with case volume fill and case tension too.
I cannot find where these were ever tested by anyone here