My barrel likes the 120gr bullets best. The old Nosler Solid Base bullets were lights out in my 6.5JDJ, with 5-shots groups of less than 1" at 100 yards. I was very disappointed when those bullets were discontinued but the Ballistic Tips work just as well. I have used mine primarily for deer hunting, so I haven't tried anything smaller than 100 grain bullets, which shot well enough, but JD convinced me to stick with the 120's for deer. Given the modest velocity of this gun (compared to a 260Rem.) just about any of the mid-weight cup n' core designs should work well. I admit to being a bit biased toward Nosler bullets, but I think if I changed to anything else, it would be the 100gr Partition. If it grouped well, I would expect it to perform flawlessly on deer-sized game.
Something you'll discover pretty quickly is how strong the 225 parent brass is and how EASY the whole process of creating the finished cases is, especially if you've dealt with other 'cats that are more demanding, like the 30 Herrett. I have fireformed a total of 200 cases and not had a single blown shoulder. The process I use is to run the 225 brass through the tapered expanded, seat a 140gr bullet into the lands about .010" and use a medium charge load of IMR-4320. The fireforming loads gave near MOA accuracy. After they were fireformed and resized to their final dimension, I annealed the case necks.
FWIW - IMR-4320 is the only powder I have ever used in this cartridge and it has done everything I wanted. If I was inclined to try other powders, I would start with Varget, while also looking at H4895, H380 and RL-15. I doubt any of those would be significantly better than 4320.
Enjoy your new barrel...I think you'll find it's one of the more rewarding wildcats to work with!
