Rusty,

I bought a new 550 in 416 Rigby in 2000. As usual, I properly tightened all screws, then shot the rifle. After 8 rounds the stock cracked just below the bolt. I took the action out of the stock and found that the recoil lug area was badly cracked, also.

When I sent it back to the warranty station in Kansas, the tech told me that they were prone to this and to glass the recoil lug area of the replacement stock. I did and had no further problems.