I've spent this morning loading and shooting that 220. As the same rifle with the previous barrel did, 55 grain BT's and 63 gr Sierra SMP's shoot great. The Nosler Partitions just won't group worth a darn, though I haven't yet tried R17 behind that bullet. And I've always wondered how the 65 gr Sierra GK would shoot in that rifle. My logic was that if the 63 grainer shot great, why wouldn't the 65 grainer. Well, my logic was flawed. I've shot some loads with the 65 gr Sierra and I don't even know where the darn bullet WENT. Must not be stabilizing. The 65 grainer is a small bit longer (maybe 1/8 inch) than the 63 grainer, and I guess that's the significant difference between stabilization and not.
So, I'll shoot a few pigs with the 63 gr Sierra SMP and see how that goes. And when the sellers are restocked with bullets, I'll try the WW 64 gr PSP and maybe the Barnes bullets.
I'd consider doing what Wyoredman is doing, but the smaller bullets (i.e. the Nosler 40 gr BT, which I have plenty of) isn't good pig medicine. And try that 63 gr Sierra SMP. Shoots really great in my 220. Kind of a stumpy little bullet and I'm sure the BC is rather poor. So be it.