Which 9mm autoloader has the least support

[clutch]

I have a M&P shield and a XDM, I don't have a Ruger or Glock offering in 9mm to compare. Which one has the most case head support and which the least?

I picked up and reloaded a case that I didn't notice the bulge in it and wondered what it might have been shot in. 0.008" expansion, likely a very warmish loading.

 

[mongoose33]

Geez, from the subject line, I was ready to offer up "Hi Point."

Glock has had issues w/ less than full case support, but that's only apparently been in some models (such as .40). Some others apparently aren't fully supported but they're close.