Any bonded or all copper bullet I've seen stays together amazingly well on steel. I pick up bullets from many different friends guns at my gong we can shoot to 600 and they all look good. I'm not sure it is a great test. Most shooters that go up there use accubonds or Hornady Interbonds. Some Swift Sciroccos. Most want to use the same load for elk occasionally and deer annually so they lean toward lead bonded bullets with good BC for deer that are still elk capable.