FLUTED CHAMBERS - as per The Glock 44 .22" Rim Fire:

The more I read stuff (- while trying to justify saying "I know what I'm talking about.")
.. or maybe even something I have actually been heard to say (- with a smile) to my wife (ex) - "I only argue when I'm right."  .. the more UNSURE I actually become about some aspects of life.

The current topic is .. FLUTED CHAMBERS:

H&K P7 9x19mm Fluted Chamber. 

Those Flutes & The Larger Diameter of The Chamber Opening 

- Are Stated To FLOAT The Fired Brass Out Freely.

Question: What is the purpose of machined chamber flutes?

A/- Are fluted chambers designed to delay the opening of a blow-back action by increasing the contact grip between the brass cartridge case & the chamber walls until the gas pressure drops?  .. or

B/- Are combustion chamber walls fluted to permit combustion gasses to move between the two surfaces thereby "floating" the brass away from close contact and lubricating /easing that action opening?

- Certainly I have read BOTH explanations.

Fired 9mm Brass From H&K P7 Pistol

So far I'm beginning to think that both explanations are correct ... because there are different types of chamber "fluting" for different reasons. There are known to be LONGITUDINAL FLUTING - RADIAL FLUTING - HELICAL FLUTING - & even a form where multiple .015" holes are 'dimple' drilled into the chamber wall.

The fluted Glock G 44 chamber has a 'Ghost Hole' loaded chamber indicator:

And A Fluted Chamber ..

- So that's clear then ....

.. Just exactly what is the purpose of the G44 chamber fluting remains to be determined eh,

A Link to a Technical Treatise on the topic:
  http://s3.amazonaws.com/hk-manuals/files/Armorer/Misc/Fluted_and_Annular_Grooved_Chambers_in_Firearms.pdf

Marty K.