don't sweat the heavy barrel thingee too much- read a few books, find out about the m15/m14 conversion, and find out as I did that the heavy barrel MADE NO DIFFERENCE in accuracy- as far as the first m14s that came from Israel go- well I've got a niw trw m14 that never saw a barrel wrench and all the part numbers match, as well as a springy where all the part numbers match , and and h&r same story- if these were disassembled, and re-made from parts bins, why would they bother making sure all the parts came from the same rifle?- sorry, but military parts bins don't work that way