Ok here's the run down of what just happened.
I have a brand new Magnum .91 4 stroke, and Im breaking it in on my Hangar 9 AT-6 Texan.
The prop is a 14x8.

The plane is on a stand, so it has had no contact whatsoever with the ground or anything that could be sucked into the blades.

After running about 1 tank through the engine, I cranked it over again after it cooled. I used a chicken stick with a rubber end.
When I spooled up the engine to full throttle, both sides of the prop seperated at exactly the same place.
The engine reved incredibly high before I was able to shut it down, but actually no more then a second and a half.

Anyone ever had this happen before? Ive seen props throw a blade, but never both ends at exactly the same moment. I wonder if the engine is damaged now.
Thank god no one was in the line of the prop arc when it let go...I still cant find the blades.

Here is a picture below...the scratches are from me trying to get the remains off with a channel lock...before I took the prop off it had no scars anywhere, it was all perfect looking, but without blades.

That is wacky, to say the least. Thankfully nobody was hurt. People at the field think I'm nuts when they see me head for the ground as they pick up their screaming airplane and raise the nose to eye level to check the needle. Anyway, I have been using various sizes of Dynathrust for years with never a problem. I suggest that you contact Dynathrust, as they would probably like to examine the prop to see if they can pinpoint what happened. They don't want prop fragments flying into people's eyes, either. And maybe they might replace that prop with a new one.

yeah good idea, I guess I should print this post off and mail it to them.

Glad to see you got the prop off. Are we still on for tomorrow evening

Yep got it off and I will see you guys tomorrow night

I have heard that people have had problems with these propellers before. That is why I sold mine. (NIB)

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Thereby passing the problem on?
Things like this should be returned to the manufacturer, or sent to the local landfill (in a broken condition, lest some Junkyard Wars guys ahold of it).

There is another thread elsewhere in this forum on Dynathrust props sheading blades. More commonly, it appears, one blade at a time. When this happens, there is usually a major airframe failure.

Why do I hear about these things AFTER I buy a number of these props. I have not had a problem with mine, but I will not use them now. It is not worth the risk of injury, or airframe.

Bedford