It's a matter of spirited debate on
www.204ruger.com. One fella's got 3000 rounds, more or less, thru his Savage and it's still shooting well enough to kill prairie dog pups @ 300+ yards, so he's happy enough with that. As a guess, "about like a .223" is probably right enough.
Gotta remember to keep them cool, and clean them once in awhile.