My dad was in VN with the Walking Dead unit in the Marines. A representative from stoner brought the Stoner G-63 for trials - trained the marines and let them take it into the field - he was impressed at the time. I can't get any stories out of him anymore but you figure 47 years later and still working out shrapnel is story enough.
It's come a long way since Vietnam because it had a lot of problems there. I liked my M2 carbine.