Difference between pre-war and post war C-stocks?

[Jim Tarleton]

Is it uncommon for a C stock to lack any proof marks or inspection stamps? I have a C stock with the S in the magazine cut off. It's a 1.3 serial number receiver with 8/31 barrel. It was a 2001 CMP purchase.

Look very closely in the barrel channel and tell me what you see.

Jim