yep. i'll defer to docGKR on terminal ballistics, but i still like to shoot a round i can afford to use when training. i have untold thousands of rounds of m193 fired and know how reliable it is. i can't afford to run SOST or TAP or any of the cool stuff in volume.
however, when i switched to a 10" SBR, i also switched to using 75g OTM. No real idea how effective it would be but i am confident i can get hits with it and quickly.
I can't afford to fire thousands of rounds of quality defensive JHP (Gold Dot, HST, Ranger) in my carry pistols either, but that doesn't mean I carry Winchester White Box FMJ.
Once I have a proven-reliable firearm, using ammunition of a type that is affordable in volume, I decide upon a reasonable amount of the 'good stuff' to test for function, and then use it, trusting in the reliability of my rifle, the quality of the round, and the reports of reliability from everybody else using that round, and assume whatever risk of malfunction there might be in order to gain the increased terminal effectiveness.
*knock on wood* I haven't yet had a single malfunction in any proven-reliable firearm when using a premium/quality defensive round.