What’s the temperature like outside when it happens?
Black crisp holes sound like hot metal hit your target
What’s the load? Is it copper or straight lead? And is it soft pure lead or lead with an alloy mixed in which makes it harder. I’d suspect a load with a soft heavy pure lead is hitting your target and retaining a lot of heat, try a backstop of old clothes or something and see if your black crisp holes are also having soft molten deformed bullets further down range which might not be so good for hunting, I’ve been told that soft hot lead that hits an animal won’t penetrate bone cleanly it expands too much, kinda the old Buffalo bullets vs hollow point argument and how the buffalo bullets that are blunt soft lead projectiles are just as damaging as a good expanding hollow point that disperses all its energy on impact and expands into a fat disk when it hits a solid object and doesn’t penetrate through ... but that’s just my two cents and a lot of unscientific knowledge I’ve picked up from old timers
Hope some of this helps you in your deductions and doesn’t send you on a wild goose chase
These differences are most likely related to target orientation and have nothing to do with loads. Some things I've noticed that will produce "out of round" holes or more ragged tears are angle of bullet entry, rigidity of the target, wind moving the target, etc.