Drawings/dimensions for Ruger Mini-14 magazines

[RSABear]

Over time the feed lips of my Mini-14 magazines seems to get bent inwards and down to the carrier. I do IPSC and sometimes man handle the mags during a shoot. On some of my mags I get a feed problem - the cartridge does not exit the lips properly and does not enter the chamber, but gets stuck pointing at an 30 degree angle upwards and to the left.

Can anyone assist me with the dimensions to make a "Go - No go" gauge?

PS: I hope it is lips - Google seems to think so. These are the factory 20 and 30 round mags.