Here goes, I wish I had a video camera so you could see this better but this is how you snatch big weight. Thing is when I go to snatch a heavy weight there is no way to hold onto it if you muscle it over your head. If you could learn to drop it would make a huge difference in what you could ohp without having to get stronger.
I pull the weight from the floor slowly at first, keeping the hips loaded until the bar clears the knee then I explode up with my traps,hips, and calves. The arms are like ropes, they accept tension but do not apply torsional force (reverse curl).
Next as the bar reaches just above the waist and you have finnished pulling the weight...in other words any weight you can get to this postion, you can get over your head.
Note: the arms are not pulling they just bend to let the momentum carry the weight to its peak while you explosively try to smash your ass to the floor
now I just "catch" the weight since 185 is easily pulled it is a very light weight to snatch....so if you can pull 400 lbs up to the height in picture 2 you can press it over your head.
Also don't wear shoes like this it makes it hard to balance an overhead squat...I forgot my good shoes
Anyway I hope you got some Ideas from this...either way good luck