Quoted:
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.
View Quote
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.