Comp Cam/lifter failure

ns1rm21, had TWO Comp XE 268 big block cam go bad on the run stand within minutes. Summit sent him a second cam and 3 weeks later it went bad on run stand.

I sold him a NOS MP cam from the late 90's early 2000's. Been fine for two years now.

Bought two Bullet solid cams since. One with lifter holes and has many miles. Second has just run stand on it so far. No issues so far with those.