I agree it’s not big at all. Also there’s a 2/3 chance it goes into the ocean not creating any crater at all.

I just ran some scenarios through AI. I’m not any kind of physicist or anything like that, but I tested some gotchas and the results seem to be reasonable (in a What If kind of way of thinking - the numbers should be correct in order of magnitude).

Only ~8% of asteroids falling on the Earth are metallic.

You can get the size of the original asteroid from the size of crater (mass of the moon and the nature of regolith are known). The biggest variables are speed of the asteroid and angle of impact (I took a reasonable guess and assumed they are not changing in these scenarios). Whether the original asteroid was mettalic or not we may never know.