Doc540, yes indeed a fine B-day present.
Doc TH said
The M1 carbine is an excellent personal defense weapon. While it was not intended to function as a battle rifle, it was still very popular with many front line troops in WWII. It was light and handled easily. In the Pacific, it was found that it would penetrate Japanese helmets and the occasionally used Japanese body armor, which the Thompson 45 would not. It was also accurate at much greater ranges than the Thompson. The cartridge of course did not have the power of the '06, but the stories of poor performance were for the most part hogwash and not borne out by actual combat statistics. American para's liked the carbine, and its utility is testified by the fact that it became, in and after WWII, a favorite arm of the French Foreign Legion and the SAS in Malaya. I have always found it curious that the scuttlebutt artists who criticized its low power never made the same allegations about the German MP40 ("Schmeisser") which fired a considerably less powerful round.
Good write up.