The US military has used bi-metal jackets in 30 caliber bullets off and on over the years. I would not worry.
The US Military has more money for replacin barrels then I do.
I ain't putting that crap in any of my guns.
Barrels and chambers are relatively soft. Brass/copper/lead is softer yet.
Steel is harder,
Which one is gonna cause the most wear?????
To each his own, but I think too much of my guns to shoot steel bullets or steel cases.