"I am thinking if these bullets are opening this well with minimal resistance at 1950 and decent resistance at 1830 they have a very good chance of opening well on much larger game somewhere below the magic 1800 fps mark."
Yes, those North Forks are great.
And now there are four different Shock Hammers from Hammer Bullets in .411-caliber:
That last one (377-gr) has a G1 BC = 0.425 !
Oh shucks, it is 1.61" long with a nose projection of 0.7599" and there are 9 PDR troughs along the shank.
It is the only one not suitable for most .405 WCF rifles.
Recommended twist for Dangerous Game is 1:14" or faster.
For Big Game 1:16" twist or faster recommended.
For DG you gotta spin the bullet faster when the bullet is that long.
For mere BG, not so much.
Can't help but think of a slightly longer-throated ".400 Whelen+" to fit into a +3.6" mag box on an M70.
As penance I am ordering the NECG barrel hardware for my Ruger M77 Hawkeye .400 Whelen right now!