Crap happens. However, It is a zero fail game in training, and this type of stuff puts a horrible light on a great guy with Mad skills. Very unfortunate
I say that steel is harder on chambers than Brass!!!!
1) Metallurgically that is a no-brainer
2) Seen several Glock barrels ruined by Steel ammo, from chamber wear and then failures as a result.
Qualification to assess
Degreed gunsmith
Pistol smith for years
personal experience