I use these cots regularly and it is always tight to put the last end-bar in place. I pry the bar in place with another bar or something long and solid like a shovel handle. My hunting partner pulls on the bar like a rowing machine with his feet braced on the cot legs.

I will admit that a few times I just have not been able to get the last end-bar pin in place and used the cot with the end-bar placed against the tops of the cot legs.

Mike