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Posted: 4/11/2011 6:42:44 PM EDT
| After studying some of my semi auto handguns I figured out that when a round is chambered from the magazine the rim of the cartridge slips up under the extractor so the extractor does not have to bounce over the rim as it does if you drop the slide on a chambered round. This is why you should not drop the slide on a chambered round. On an AR-15 type bolt I don't see how the rim can slip under the extractor claw on loading because the extractor and the rest of the boltface is recessed behind the locking lugs. Am I correct in assuming that the extractor does have to bounce over the rim to engage it? If not what am I missing? |
| Thanks for the instant reply. Maybe I'll start carrying around a spare extractor and associated parts though I can see how the extractor geometry makes it work without too much stress. I'll have to take a close look at some spent brass the next time I shoot my AR. |
| What you're talking about is the difference between controlled round feed and push feed. With a CRF type action, the head of a chambering cartridge slides up the face of the bolt and is captured by the extractor on the way up. 1911's and some bolt actions work this way. Push feed designs strip the cartridge out of the magazine with an edge of the bolt and the head of the cartridge isn't on the face of the bolt and the extractor not in the groove until the round hits its headspace control point stopping the case from moving farther forward and the final act of camming the bolt locked forces the extractor over the rim. The extractors in such designs are hinged to account for the jump over the rim and it doesn't hurt the extractor. The AR extractor is a perfect example of this type of design. Most autopistols work this way as do Savage and Remington bolt actions. |
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Quoted:
What you're talking about is the difference between controlled round feed and push feed. With a CRF type action, the head of a chambering cartridge slides up the face of the bolt and is captured by the extractor on the way up. 1911's and some bolt actions work this way. Push feed designs strip the cartridge out of the magazine with an edge of the bolt and the head of the cartridge isn't on the face of the bolt and the extractor not in the groove until the round hits its headspace control point stopping the case from moving farther forward and the final act of camming the bolt locked forces the extractor over the rim. The extractors in such designs are hinged to account for the jump over the rim and it doesn't hurt the extractor. The AR extractor is a perfect example of this type of design. Most autopistols work this way as do Savage and Remington bolt actions. This |
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