Coldest for me was a couple coyote stands on a day that got down to -46 celsius. They were feeling hungry that day. Got a couple dogs and some minor frostbite.
50 grain ballistic tip here as well. 24” barrel and I’m at 3960 FPS, not the fastest load I tested, but it grouped a little better at that speed. Loading with imr 4166
If you have access to older nosler loading manuals, you will notice that the 300 Wby took a dive in velocity around the time the 30 nosler was introduced. Must just be a coincidence.
22-250ai
6mm creedmoor
6.5-300 Wby
340 Wby
416 of some sort, probably a Wby as well, but only because elephant was in question. Strictly North America and I’d have a 30 cal instead.
I’ve got a 257 wby. with 30” barrel, pushing the 80gr. ttsx at 4240fps. Not exactly what you’re looking to do but sighted 1” high at 100 it is only 8” low at 400. Was set up for a similar purpose so that I don’t have to worry about holdover on called wolves.