Random Semi-Automatic Pistol Nomenclature Question

[Seven_Sicks_Two]

It seems as though every part of a firearms has a specific name, some of which are more obvious than others. However, my shooting buddies and I have run into one that has left us all stumped. Various books, websites, owner's manuals, diagrams, etc. turned up exactly bupkis. So, I was hoping that you guys (and gals) could help us settle this question once and for all. Here goes:

What is the name (if any) for the hole cut in the muzzle-end of a semi-automatic pistol's slide that allows the barrel to pass through?

Feel free to mock me mercilessly if the answer to this question is common knowledge.

[1911Nut]

Barrel hole?

[Tamara]

I have never heard a specific name for that.

[Totem Polar]

On anything but a 1911: muzzle puzzle.

On a 1911: rattle trap.

[Seven_Sicks_Two]

I have never heard a specific name for that.

Tam, you were one of the people that I was counting on to have an answer to this one.
Darn.

[Joseph B.]

Barrel hole?

When discussing after market barrels for my Glock 22, barrel hole of the slide was used to describe the hole. I have also heard it referred to as the barrel bushing, but I think that's more from the 1911 design, as the Glock doesn't have an actual bushing.

Its a good question, I hope someone can give an accurate term for it.