All true. They were replaced in the late 1970s by M14 rifles, using a dummy rifle grenade filled with orange 75-pound test *messenger line,*, used to haul back 550-pound test line, used to pass back a 2000-pound test line, at which point fueling lines and communications and other electrical cables could be transferred. It was a point of pride with some of the M14 shooters to be able to place their rubber grenade through an open hatchway or hit a fiberglass panel that would shatter on impact. Sorry, Chief, the wind caught it....
The US Ranger and SpecOps community has been using the FN SCAR-H 7.62 rifle since 2009. Rather than going through a new procurement cycle, just order a few more.