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Posted: 7/26/2005 6:00:28 PM EDT
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Do these things really work? I have a brand new Bushmaster that is jamming every round. The spent round is getting hung up in the extractor and a live round is always underneath it. From what I have heard the d-fender is supposed to solve this problem. Any experience with it??? http://www.ketmer.com/armforte/dfender/dfender.gif |
| The d-fenders do work for many extraction problems; however it sounds like you have an ejector problem. I have seen a couple of times on brand new ARs where tiny brass shavings lodged alongside the ejector causing it to stick. If it sticks out it causes a failure to chamber. If it sticks in it causes a failure to eject similar to the problem you describe. |
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Hopefully, some smarter folks will be along soon. If not you can re-post in troubleshooting section. Dropped extraction is the plague upon carbine length gas systems, particularly with shorty barrel lengths. Long story, but the bottom line is that the violent nature of primary extraction causes the extractor to temporarily let go. This results in a failure of ejection.......oddly enough.......although the ejector is not the cause. You get a failure, and what you find is an empty case interfering with the feed of the next live round. A D ring, O ring, or high performance extractor spring mitigate against this tendency to drop the shell. One of my shorties had this problem.......bad........and is now an obedient puppy thanks to a D ring. I have been told that this can happen in some rifles with full-length gas systems, though I have not personally seen this. The fix may also involve chamber polishing, etc. Sam |
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I just run a SAW (Specialized Armament...part # SA05006) heavy duty extractor spring with black insert and a CRANE O-Ring.......$6.50 total. Day and night difference between the SAW spring and the standard spring....I don't think the D-Fender can beat that setup and at $12.95, the D-Fender is just ridiculously over priced...$5.95 would be more realisitic.... ...and honstly, I don't think the CRANE O-Ring is even necessary with the SAW spring but I already had the CRANE O-Rings so I figured I might as well use 'em...  http://www.specializedarmament.com/jsps/sku.jsp?field=Part&value=SA05006 I also only run Colt bolts in my AR's...and no, I don't drink the Cool-Aid...I'm not a "Colt Fanatic"...but even in my Bushmaster, I run a Colt bolt. Always have....even when I buy complete uppers, I'll sell my "whatever" brand bolt and replace it with a Colt...I did the SAW Spring/CRANE O-Ring mod just because I ran out of things to do to my AR's... 
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Sorry!|
To answer your question: yes they work. Two years ago I had a similar problem where the empty case was not being ejected. Sounded like an ejector problem but because the extractor wasn't holding onto the spent case long enough for the ejector to do it's job it turned out to be a weak extractor spring. I tried the D-Fender and it's been in that carbine ever since and has 3000K through it by now. That said, a Colt HD spring or Wolfe power spring will solve your problems just the same
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I tried different O-rings and the materials all broke down after sustained firing. I'm sure the D-Fender has passed critical testing, but I'd be happier NOT depending on a piece of polymer that will eventually wear down. The Wolff XP extractor spring is a 4 coil spring that AFAIK has never failed to work, and will most likely do the job w/o using a D-fender, O-ring, or rubber insert. It also carries a lifetime warranty FWIW... |
search twl or go to this thread which he has replied to and you can im/email him great guy to deal with! |
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