Quote:
the standing breach is not 90 degrees to the watertable. If it was the gun would never close.

"WHY"!!
On the few I have bothered to check the standing breech formed an angle of "Less" than 90°, IE the top of breech was tilted Forward. Elementery geometry would show that if it will close with an angle of less than 90° it would close with a 90° or greater angle. This angle is quite obviously put there for a purpose other than the ability to close the gun.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra