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Posted: 9/10/2009 10:36:33 PM EDT
| I have an M4 that I've only shot about 400 rounds through. about 3 times out of every 30 round magazine i get a jam. It kicks out the spent shell and feeds a new shell into the chamber but the old shell will jam up the ejection port and keep the bolt from riding forward. The thing that confuses me is that there is a new round in the chamber every time. I am really confused on why and what is causing this. I have a feeling the weapon needs to be fired more to get broken in, but I'm not sure. Can anyone give me some advice. |
| Sounds to me that you have one of two problems... your rifle is either stovepiping (the end of the shell sticking out from the ejection port), or your extractor is dropping the shell during the extraction. Check the tension of your extractor and ejector with an empty shell. Hopefully someone else chimes in...good luck |
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Guessing that this is not a Colt unit.
With that being said, pull all the way back on the charging handle and confirm that the face of the bolt does not retract back past the back of the ejection port. If that is not the problem (spent casings hitting the back of the port and being danced back into the action, then install a #60 O-ring around the extractor spring for a bit of live fire testing. Now with the O-ring in place, load a single round into the mag, charge and fire the round. The bolt should be locked back on the catch (confirming that the rifle is not short stroking). If the bolt locks back, load a full mag and test some more. If the bolt does not lock back, then you have a short stroking problem, and will need more information on the rig to trouble shoot that. If the O-ring does solves the problem (spent casing no longer dropped from the bolt face before the end of rearward stroke) and is needed after more than a few hundred rounds as the rifle breaks in, then you need to replace the extractor spring with a stronger spring. A True Colt black insert Extractor spring would fit the bill, while a Wolf extra tension spring will too. |
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