Clearly, an extractor is necessary to eject a cartridge by hand cycling.

When firing, will most self loading guns eject a shell if there is no extractor?

I'm thinking that it is chamber pressure which actually pushes the shell out, not the extractor yanking on the rim.

I could experiment, but I thought I'd ask here instead.

I had an extractor break on an AR and the brass would not come out of the chamber.
Once a new extractor was installed it would extract again.

Definitely depends on a lot of circumstances.  But there are production models without extractors.  Look at the Beretta Bobcat and Taurus clones.  There was at least one WWII sub gun too.

Straight blow-back actions wouldn't need an extractor, for any locked or delayed action design it depends on how much pressure is left in the barrel when the action unlocks or the delay is over and extraction begins.

Anyone ever fire a 1911 without an extractor?

I'm thinking that any tilting barrel might need the hook to control the round so it hits the ejector.

Supposedly the HK P7 with its fluted chamber will extract and eject without an extractor.

Extractor broke on my CZ-pattern pistol once and empty cases did not self extract. Necessary part unless you like single shot semi autos.

Edit to exclude blowback guns...another post reminded me that the Beretta Tomcat I inherited is without an extractor and it usually ejects the empty case...but not always. That may be case in point, depending on ones feelings toward blowback guns.

You can be assured that if the weapon would function reliably without an extractor they wouldn’t have one.
Parts left off cost nothing, parts left off cannot fail.

Extractor is clearly necessary to eject a live round.  My question was related to ejection of a spent shell.

I personally don't recall seeing a gun design without an extractor, but I'm sure there are some.  
However, there are plenty that function fine and have no ejector.  Usually the small pocket pistols in 25 or 32 ACP.  The NAA Guardian is one.

Tony

not quite.

The extractor does exactly what it’s name implies.
In firing there are two things that prevent the case from self extracting under its own recoil or gas pressure.

1. When the round fires, the brass heats and expands against the walls of the chamber (if you’re firing .223 or 5.56, the force involved is about 52,000-55,000psi depending on the ammo you’re using). This becomes VERY apparent if you’ve ever had a case head shear off and had to use a ruptured case extractor.

2. The chamber stays locked until the pressure in the chamber drops to safe levels. this is true for both gas and recoil operated auto loaders, they just use different mechanisms to delay unlocking. The bullet is long gone at this point, and the expanding gas has expanded out of the muzzle. Then the bolt unlocks and extracts the case.

As pointed out above there’s exceedingly rare examples. I’m not sure which WWII sub gun was referred to but the bobcat is in .22 and .25 which are both very very low pressure loads.

Then your question is incorrect. Clarify your terminology.
The ejector is responsible for the ejection of a spent casing from the action.
The extractor is required to remove the spent casing from the chamber so the ejector can then eject the spent casing from the action.



My original statement stands.

Only a straight blowback can get away with it, and even then it is better if they have an actual extractor for when they get dirty...  Beretta .22 950BS or 21A for example.  

Any weapon with any kind of locked breach needs an extractor.

When I test fired my semi auto STEN build, it worked beautifully.

I returned home to clean it and discovered that the extractor was on my work bench the entire time.