This thread is here http://forums.thecmp.org/showthread.php?t=175952
This part isn't quite accurate
Today, 03:57 PM
Don in SC Join Date: Oct 2009
Location: Up state South Carolina
Posts: 1,305
yes the bolt has to be modified, or it will not fit between the feed lips on the magazine. You will need a BM59 bolt whether you do a M14 or BM59 mod. The BM59 mod only needs the Receiver to be modified, the M14 mag mod requires that the BM59 parts to be modified to work with different locking set up of the M14 mag.
No bolt mod is needed on a M14 mod. I do not use any BM59 parts on a M14 mod, I make them or have them made, depends on the part.