Nosler also makes a 53 grain Varmageddon bullet with a BC similar to the 53vmax, you should check that out.
https://www.midwayusa.com/product/1...aliber-224-diameter-53-grain-tipped-flat-base
This....the only 224 bullet I have tried lately that shoots besides a Berger. Varmageddon's are not expensive bullets to boot, but they sure shoot good for me. I also have to say, 5/8" groups for a factory barrel is fantastic these days. I don't know what you believe a factory barrel should do {well, yeah, they should do .250" but dream on} but if they all did 5/8" or better I think most of the custom barrel makers would close down. I personally haven't seen a factory barrel shoot under 5/8" in about 20 years.