Some info (from a M1 board) on the rifle I posted about:
The barrel number didn't seem right to me either.

A s/n of X83 means it was one of the "experimental" carbines. Some were used to test new components, most were eventually presented to Inland employees or military officers or government officials by Inland. The first 400 "X" carbines were intended for experimental projects, in 4 groups of 100, "X", "XA", "XB", and "XC". That's pretty rare!!!

The last of the “X” carbines was presented on October 21,1958. As such the barrel date is most likely right for it too and would be close to the date it was given out. For a few hundred dollars it is well worth it as some collectors would snap it up at almost any price. A nice catch and a keeper. Keep it as is close to what it was like when it was presented and it will just continue to increase in value.

I told my buddy about this and he's deciding what to do.
If I was able to get this rifle for a few hundred dollars, it would be a steal :cool:
But why sell to me when he can get more $$$......