M60s would fall apart just getting carried... the spring that retained the pins that hold the grip on were notorious for falling off. Once the spring fell off, the pins were next. Once the pins were gone, the grip fell off.
I saw a the sun come up on a road march once, and the '60 gunner was missing his whole grip assembly. He had no idea where it went, it had parted ways some time in the night.
Especially if you install them incorrectly or don't keep them bent the right way.