The 7.62mm X 51mm round is overkill for CQB
http://www.strategypage.com/dls/articles/200512022.asp
Agreed. The Russians found that out the hard way against the Finns in the 1938-1939 Winter War. The Germans didn't pay attention to the Russo-Finnish War and as a result, were taught a hard lesson by the Russians that in CQB, a 7.62x25 will kill you just as dead as a 7.62x56r or 7.92.