That was the reason I had to tear the 440 down last time.

It is a Comp double roller set driving a .480" cam with standard Eddy heads and springs. I had about 45 minutes run time on it and was on the highway for a break in run when it happened.

We never did figure out what the exact cause was. The cam bolt washer is bent back over the bolt head so the gear was leaning on it pretty hard. The locating pin was sheared. Instead of a drilled hole for the pin Comp used a slot cut upwards from the bolt hole. We can only assume the gear shifted slightly when the pin broke and tension pulled it down on the bolt. That broke out the back side of the grear and it let go.
The strange part was damage to the rear edges of the lobes in front of each cam journal. It also took chunks out of the associated lifters.

I was out of warranty by time (2 years on the shelf) but Comp engineers had never seen that failure and replaced the cam, lifters, and timing set. No complaints with them as the went out of their way to help.

We could not rule out assembly error so I wrote it off and Sh!t Happens.

12 valves lightly kissed pistons and the front main bearing was wasted.