More than one of us went through that same sort of experience with various bullets!
Core--Lokts were pretty thick-jacketed bullets back then (though not today), but they weren't "unbreakable," especially close up at higher velocities. In fact John Nosler developed the Partition after having problems with a British Columbia bull moose with 180 Core-Lokts from a .300 H&H.
I started using Partitions during the last 3-4 years of the lathe-turned bullets, the mid -1970s, and they took a lot of doubt out of my hunting--especially for elk in the thick timber of the Montana mountains alongside the Idaho Panhandle. A hundred yards was a long shot, and after switching to what were then called 200-grain "semi-spitzers" in my .30-06 there were no problems.
That location is exactly where my elk experiance happened and your 30-06 200gr Nosler experiance prompted me to try it out. Often things are really close range or one can shoot across canyons and clear cuts. Now i have grizzlies showing up on the trail cam and found buried moose carcass and some other activity. They arent behind every bush but some areas are extremely thick and i prefer my 338RCM or 30-06 in some of those areas but so far ive no incident and like it as such.
A few years ago i lived on a ranch outside a place called Big Timber. There were mule deer and antelope plenty. I suspose a 25 might be ideal on that place that was open with breaks and bluffs. I
