Scott if it is like the 6x45, and I can't see why it wouldn't be, pretty much same case with an improved neck length. I can tell you best groups for me meant not being shy with the powder! But then anyone shooting the PPC and staying competitive today, knows you gots to feed that sucker, you need the longest drop tubes and slllooowwww dumping large quantities of N133 to make it happy.
I did the same with the 65 grainers in the 6x45, as much Benchmark as I could feed it, long drop tube and taking my time trickling every grain to get as much as I could in. I was feeding that little casae 29.5 grains of benchmark, and igniting it with Remington 7.5 SRP's. I was pushing 3300 fps from it, and really not seeing any sign of to much pressure. BUT that was on this 23 3/4" barrel, and it does have a tight chamber.
I know the previos owner had as good and better results with H322, and was running 3200+ with 62 grain bullets. But he was only shooting 3 shot groups. Which is all that matters with a hunting rifle, I just can't stop at 3 shots, mine were all 5 shots. But if you call not being able to shoot 5 shot groups with every powder charge producing 5 shot groups under .4" @ 100 yards FINICKY,, well that's something I'll have to live with.
I really didn't try anything else, for hunting this was good enough, and for a 1-8 twist barrel, something no short range benchrest shooter would ever use, I was happy, plus I have a bunch of bullets, and no other cartridge to use Benchmark, so I quit there. Mainly because I wanted to screw the 223 barrel on that had not ever been shot since this switch barrel rig was built, to see for myself. Glasd I did!!!
47 grain FBHP custom bullets and 3810 fps average with XBR 8208 another powder I have a lot of, and nothing using that powder. I was pleased. So pleased I'm going to cut that barrel to 20" and see what it does then. But so far it's agging under .5" for five five shot groups. Not as good as that 6x47 but still smoking fast and plenty good for a Varmint sporter!!
I plane on putting the 6x47 barrel back on Scott and testing some other powders with the 65 grain Bib's. I also since this is a 1-8 twist barrel, going to work some with the 85 grain Sierra HPBT game king. I only shot one load in it, 28 grains of Benchmark and only 3 shots, but .3" and 2930 fps makes we want to work a little with those bullets and maybe some XBR8208 or Varget, and see what this would do as a whitetail cartridge under 250 yards???
But I'll post on that thread, and I'm watching yours. These cartridges I have a feeling are way underrated!! GL!