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Posted: 3/27/2010 10:00:32 AM EDT
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Hello,
I read here the BDM extractor works better than the one that comes with the CMMG conversion. What works better with it? Does it extract live rounds where the oem doesn't? Does it eject spent brass better than the oem and allow for more brands of ammo to work? If the BDM works better, why doesn't CMMG use it or make theirs to work just as well? Doesn't seem right I should need to spend an additional $20 to get someone else's part that works to make mine work properly. Thanks |
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I have several of these as spares. I bought them with confidence that each one would be
machined precisely to what it should be. They're case hardened. If your extractor is working like it should, I wouldn't buy one to just replace it. On conversions that won't extract live rounds, it may or may not do any better. Sometimes, a weak extractor spring is at fault or the machining of the extractor recess on the chamber adapter. Black Dog Machine is quality and that's the biggest selling point for anything made by them. CMMG copied the original Atchisson design as far as I know. You should contact them for a replacement extractor as a start. Then if it still doesn't work, they may want you to send the conversion in for repair or replacement. SpecOps-13 |
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Quoted:
Hello, Does it extract live rounds where the oem doesn't? Does it eject spent brass better than the oem and allow for more brands of ammo to work? Thanks I'll address what I know. if the oem doesn't extract live rounds, it is not working right. either the spring is weak, or the notch on the chamber or the nose of the extractor is not correctly shaped. depending on which is the problem in your case, new BDM extractor may or may not help. identify the probem first. Main purpose for the extractor is to remove live, unfired rounds.secondary for extractor is to hold empty case against the boltface until it hits the ejector. this is a blowback action, reaction of firing, after bullet leaves barrel, "blows" fired case out of chamber. |
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Thanks for the replies!!
I also read here from a post from CMMG that the conversion unit wasn't designed to eject live rounds. Is that how most of them work where you have to dig out the round with a fingernail or screwdriver? Should they all eject live rounds by pulling the charging handle? The end of my extractor has chips out of it and it's not square. The groove for the extractor next to the chamber doesn't come to the edge like most 22 autoloaders I've seen. There doesn't seem to be much of the rim sticking out for the extractor to grab onto. How do most of the extractor grooves look on the CMMG kits? Is it close the edge where the round goes or is it a bit flat? Seems if it doesn't extract a live round it wouldn't eject an empty that well either. Thanks |
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While the part is called an extractor it doesn't extract the case from the chamber!
These are blow back firearms and the spent case is –– wait for it! –– blown out of the chamber driving the bolt back with it. The case comes out with no extractor in the rifle. What the extractor does is hold the spent case against the bolt face until the case strikes the ejector This is critical because the case will just otherwise fall off the bolt and into the action. The extractor design needs to be optimized to this function. Secondarily the extractor should pull a live cartridge out of the chamber, but it's coming out when the cartridge fires, extractor or not. Some blow-back firearms don't even have an extractor. The lil' Beretta Tomcat pistol is a quick example. And it typically stovepipes when the last round is fired and there's no cartridge in the magazine to serve an an ejector. –– Chuck |
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