Cobra Trailer Tow Chain Attach Points

I just purchased a glider housed in a 2002 Cobra trailer. It came with only one chain (I always use two crossed chains) and the chain is attached to one of the bolts that connects the tongue to the trailer (big honking steel U strap over the tongue inside the trailer). According to the owner this was installed at the Cobra factory.

Here is a picture of the chain's external attachment points. Note that I upgraded to grade 10 bolts replacing the original Cobra bolts.

https://dl.dropboxusercontent.com/u/...r%20Chains.jpg

The question is, is this a good/best attachment point for chains? It would seem that a sharp jolt puts a high lateral force on the bolt at the weakest "threaded portion". I also saw this same setup in the linked picture at https://groups.google.com/forum/#!ms...8/FKmbkTjMBAAJ.

I see other Cobra owners with chains attached via a shackle to the V shaped bracket holding the jockey wheel/post. While this is a beefy bracket, is that a good place? Is another chain location even better?

PS - Is is true that Europeans don't even use chains? Seems just CRAZY to me as you would have a deadly unguided missile if it were to come off the ball.

Thanks, John