Not a bit. Works just fine in my Bushmaster. I don’t think it’s been released for sale to the general public, but I have a LE source.
You generally need to have a faster twist to stabilize a heavier bullet. 1:7.75 should do for .223 77 and 80 gr. If your rifle has that fast twist it should shoot fine out to 600 yds. If it doesn’t it may seem fine at 50 or 100 yds but yaw pretty wildly afterwards and it may go thru the paper at some pretty good angles at 100 yds.
Molon Labe!