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Eric
8 April 2008, 00:33
Discussion link. (http://www.weaponevolution.com/forum/showthread.php?t=374)

One of the weak points in the M16/M4/AR15 family is the extraction system. This issue is more pronounced in the carbine version of the weapon, especially under full auto fire. When extractor tension is inadequate, the extractor claw can slip off the rim of the cartridge. This results in a failure to extract the expended brass from the chamber. During the feeding cycle, the next round in the magazine is driven into the back of the round that is still remaining in the chamber. A failure to extract (also known as a dropped extraction) is more common on weapons with a chamber that is rough, out of spec or filthy. Weapons that are attempting to extract while chamber pressure is still high can also experience this problem. While failure to extract malfunctions might only occur occasionally, preventative steps can be taken to greatly reduce the likelihood of it occurring in the first place.

Some manufacturers have acknowledged that there is an issue and they have put upgrades in place to remedy this. The upgrades increase the tension on the extractor by use of a stiffer extractor spring, stiffer extractor spring insert, an O-ring or other insert. However, there are still many manufacturers that fail to put these simple upgrades in place. Many still install the extractor spring and blue insert that was designed for a rifle, in the carbine as well.

Luckily there are several options for those who are in need of a fix. This list certainly is not all-inclusive, but it contains several solid options. I consider these upgrades cheap insurance, even if problems have not yet manifested themselves.



Bravo Company
BCM Extractor Spring Upgrade Kit $4.95/$11.95 – 3 pack
http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20upgrade.htm
Included: five coil chrome silicon extractor spring, black extractor insert and a Crane O-ring.
Bravo Company has introduced an upgrade kit that uses a chrome silicon extractor spring that has been heat treated, stress relieved and shop peened. Once the spring is pressed into the extractor, it takes some extra effort to get the extractor installed on the bolt. This is simply due to the stout spring that is used. BCM has made this kit available as a single pack, or a three pack. For those of us that have multiple weapons or are armorers, the three pack is much appreciated. The BCM kit is a great value.
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/BCM-2.jpg http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/BCM-1.jpg


Buffer Technologies
Extractor Upgrade Kit $12.95
http://www.brownells.com/aspx/NS/store/productdetail.aspx?p=24635&st=071-000-043ec&s=51153
Included: extra power extractor spring, black extractor insert and an O-ring.
This is a newer item from Buffer Tech.
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/BufferTechsmall.jpg http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/BufferTech1small.jpg


MGI
D-Fender D-Ring $12.95
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=9949&title=AR-15/M16%20D-FENDER%20D-RING
Included: one D-Ring.
MGI indicates that the D-Ring increases the extractor tension four fold. The ring slips over the existing extractor and extractor insert. The D-Ring is made out of a black material. I recall having an early D-Ring that was blue. The material used is said to be impervious to oil, solvents and heat generated from firing. The D-Ring has been around for several years and MGI has worked with Crane in extensive reliability testing of their product.
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/D-Ringsmall.jpg http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/D-Ring.jpg


Wolff
Extractor Spring – Extra Power $10.99
http://www.brownells.com/aspx/NS/store/productdetail.aspx?p=16488&st=&s=
Included: 3 pack, extra power extractor springs.
Wolff is well know in the firearms spring industry. They have been producing their XP extractor springs longer than most manufacturers. They’re unique in that they do not grind the top and bottoms of the springs flat, however I have never found this to be an issue. The recommendation is to use the existing extractor spring insert along with the spring. In talking with the folks at Wolff, it became apparent their technical expertise as it pertains to springs surpasses my level of understanding. They indicate that they use “rocket wire” in their spring.
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/Wolffsmall.jpg http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/Wolff.jpg


Colt
Extractor Spring Assembly $6.69
http://www.brownells.com/aspx/NS/store/productdetail.aspx?p=4840&st=160-304-025&s=10818
Included: extractor spring and black extractor spring insert.
This is a factory part as supplied by Colt. This part number now supercedes others and is used for rifles as well as carbines. The extractor spring tension has been increased and the spring has a unique copper color to make identification easier.
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/Coltsmall.jpg http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/Colt1small.jpg


Left to right: Buffer Tech, Wolff, Colt, BCM
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/group.jpg


Extractor with Colt OEM extractor spring and D-Ring
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/ColtD-Ring.jpg


Extractor with BCM upgrade.
http://img.photobucket.com/albums/v503/AR15forme/Extractor%20Springs/BCM3.jpg

Quib
23 November 2009, 19:27
http://quib.weaponevolution.com/Assorted/Ex Spg 2.jpg