Some gun shop expert told me 600/660 bolt handles were notorious for shearing or cracking at the junction of bolt and handle and that's why the rifle did not sell well. I told him his was full of chit.
First I've ever heard of it.
When I worked for a gunsmith many years ago, theonly Remingtons that came in for bolt handles coming off were the 788's. I've owned an M600 nd M660, both in .308 Win. Never had a problem with the handles coming off, even when I loaded a bit too hot.
Paul B.
