I have worked myself into quite a froth and I think that I am over thinking the question itself. Here is how the question is worded.
On a blowback operated gun, what extracts the case from the Gun? a. the extractor b. vacuum created by the opening slide c. the case extracts itself d. none of the above.
In regard to the question itself, “extracts the case from the gun,” sounds more like ejection as it is leaving the gun and not the chamber, slide face, etc. If this is the case then I would say: d. none of the above because the ejector would then execute this function and at that point wouldn’t the extractor play an equally import role by holding it up long enough for the ejector to get at it?.
If “extracts from the gun” means from the chamber of the barrel after it is fired then I would be tempted to say: c. the case extracts itself, (as the resulting pressure from the propellant expanding causes the empty cartridge case to expand and move rearward, in turn pushing the slide back rearward with it?).
I will apologize in advance if my logic or lack of it produces more questions from your reply but I will wait to see how you respond…thank you!
Glad you are using your head and trying to reason things out. What Bob means is what extracts the case from the chamber. Ken
Reply:
Now that I know it is the chamber that the case is being extracted from, I would still say that the case extracts itself, even though I know it is the expanding gas of the propellant inside the case , we still say when one farts…”I farted”, thus the case extracts itself.
I of course want to get the answer correct, but I more want to understand, so I am going to plead a case for some other answers in hopes that I will gain a better understanding. Thank you in advance for your patience.
If in this same scenario, the gun was not fired and we were extracting a live round then the extractor would perform this task, correct?
I am also a bit unclear as to when the vacuum pressure occurs after the gun is fired. Would that be the small moment just as the bullet has left the barrel? If the above answer is yes then it would be too late to play a part in the extraction of the case. Is this correct?
Are there other factors that have a play that I might be over-looking?
By the way, check the PISCO e-mail, as I wrote and sent you an AGI song (for Gene’s birthday) as an mp3 file.
Answer:
What Bob wants to know on the test is what extracts a fired round. It does sound like you are over analyzing this question, but I don’t think that is bad you are using your head and reasoning things out. This will help when you are actually fixing a gun. (Although I have over analyzed problems before and it helps to just stop and take a break and start over. Sometimes Bob will come and look at it and often it is something really simple and basic.) So don’t be or get discouraged.
Answer:
OK, you’ve worked on this long enough, stop agonizing. The correct answer is “D” None of the above. You were on the right track the first time with the case extracting itself, but what actually causes the case to back out of the chamber and drive the slide back is……………..Right! The high pressure gas in the barrel from the combustion of the powder. – Jack
