I used to have a 1:7 twist 223 and I shot from 52 gr amaxes up to 90 gr bergers all max loads , and never blew up a bullet and never tumbled anything.

Maybe the jacket is getting damaged. Just a guess.
What does the crown look like ??

How does it group or does it shoot all over the place.

Do you actually see a sideways bullet hole ??

Seems odd that a 50 gr bullet would tumble in a 1:7 twist.