I use 180 gr Core-Lockt. I shoot for the "boiler room", not the shoulder, if that matters. My hunting mentors and family members all used Core-Lockt, and all had good success. Not that reloading wasn't done, but the Rems worked fine so why fix what isn't broke. A lot of the same friends have dropped elk with patched round ball from traditional muzzleloaders, not a lot of fancy bullet there.
Accuracy? I realize I have high-graded my groups from yesterday, but it ain't the rifle/ammo combination. 1.75" or thereabouts at 200 yards. I am not no super good shot, either.
Personal experience is of course valuable, but the fact that YMMV has to be considered, and those old Remington bullets have killed a whole lot of animals. Take a good shot, put it where it belongs, and I think you will find a dead critter. Take a "different" shot, well...