Subject: Are radioactive dating methods really as accurate as they appear to be?

Are radioactive dating methods really as accurate as they appear to be?

I heard that to test this, lava rock sample from a volcanic eruption
200 years ago was sent to three separate laboratories... I cannot
recall the exact figures but when potassium-argon dating was used the
three participating laboratories each returned ages varying from a few
million to several billion years! That is quite a large error margin...
considering the rock sample was in fact only 200 years old.

Re:Are radioactive dating methods really as accurate as they appear to be?