Warming up...

So, I was trying to see what my max bench was, my real one. I was shooting for 400#. I wasn't sure how to warm up and I think that is maybe why I didn't complete the lift. I did 10 reps at 140; 5x190; 5x225; 3x275; 1x315; 1x365 then attempted my lift. I don't know much about preparation for powerlifting or anything like that, just wanted to break the school record before I graduated. Any help would be great....

I think you did way too much, too early bro. I would have done something like this:

10 x 145
6 x 225
3 x 305
1 x 355
1 x 400

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