What is the correct term for the small protrusion above the chamber of some semi-automatic pistol barrels? I suspect barrel hood, which describes the squared, rearward portion of a Glock or 1911 type barrel for example, may not be correct. Further, what exactly is the purpose of this feature? Does it serve a similar function of locking the breech to the slide while in battery? I read an article many years ago concerning this feature though I don't recall the specifics - other than it is more prevalent on European pistols. Thanks!

I don't know how much help this will be. I have heard this called a "barrel hood" as well. I'm not sure what real purpose it serves. The stresses of cycling are borne by the locking lugs, in front of the chamber.

I've been a Hi Power fan for a very long time, and still don't know what that little nub's proper name is. Or,what it's intended function was. Obviously not needed as it was deleted on more recent production.

Function? Purely speculation on my part. I assume that it was to guide the tip of the round into the chamber instead of allowing it to wedge itself into the back of the barrel. A steep ramp and an aggressive angle on the magazine follower seem to go hand in hand. Kimber could have used these with their first attempt at a 10mm 1911. Mine kept throwing the tip of the round into the back of the barrel about every three rounds. I had to polish the ramp and adjust the magazines for this one to function reliably.

Nomenclature? I don't have a clue.

Just out of curiosity, what firearm & caliber is the barrel for?

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Originally posted by .38supersig:
Just out of curiosity, what firearm & caliber is the barrel for?

The pictured barrel is from a 1973 C-Series 9mm Browning Hi-Power. The feed ramp is of the earlier "humpback" variety which I understand was engineered for use with FMJ ball ammo. As mentioned, FN ultimately deleted the chamber "nub" - a change which I now suspect may have been commensurate with the introduction of their redesigned "straight" feed ramp in the 1980's. If so, it would make sense the purpose of the "nub" was to eliminate the tendency of a round to jam nose upward in the chamber. This is my first Hi Power and I'm learning much. Thanks for your replies.

See, with Glocks and SIGs and such, I always figured it was to aid in lock up consistency/repeatability to ensure accuracy and then ejection, cuz they're angled up towards the ejection port. Figure the next round is pushing up, the barrel is starting to tilt down, it makes sure the front end of the case is being nudged towards the exit.

But that's not quite the same design on the BHP there. And I'm just supposing anyway. I don't really know the reason for the design or shape. I would consider it the barrel hood. Or breech nubbin, if you prefer.

I always have heard it called a barrel hood.

quote:

Originally posted by hjs157:
What is the correct term for the small protrusion above the chamber of some semi-automatic pistol barrels? ......
....
I read an article many years ago concerning this feature though I don't recall the specifics - other than it is more prevalent on European pistols. Thanks!

The entire top of the battery is called "barrel hood". The nose you are referring to is called „barrel hood extension“. It supports the battery and is used for hoizontal alignment of the barrel. It’s not a feature of European guns only but one for firearms with a swing down barrel per se. One of the few exceptions is the Webley 1906. Falling block system like a P38 or an M92 don’t need this feature because horizontal alignment is provided by the frame. Neither is it present in pistols with rotary barrels for design purposes or pistols with a semi stiff blowback action like the HKP9 or Vz52 or pistols with a gas break like the HKP7 or the WF-47.

Further information about "why the gun is the way it is, why it works and and how the funny parts are called" can be found in Peter Danneckers publication: Versuchlussysteme von Feuerwaffen.(bolt systems of firearms). It's a technical publication based on schematics and physics and math, without a lot of pictures stories. Dannecker is engineer and technical advisor.

This message has been edited. Last edited by: OTD,

1911s also have this "barrel hood." Some of them have a wide gap you could almost use for a loaded chamber indicator. I don't see how it would have any bearing (pun intended) on barrel lockup.

I’ve always called it a barrel hood tang. On my SIG X5 Comp it serves to locate the breech end of the barrel in lockup.

“…Additionally, the barrel hood tang…”

http://dave2.freeshell.org/1911/barrel34/barrel34.htm