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Posted: 12/28/2004 5:31:38 AM EDT
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I was shooting my Bushmaster M4/A3 16" 1:9 yesterday, put about 80 rounds through it fairly quickly I suppose. About the 100th round the extractor locked up, the mag's (Bushmaster/Labelle..one that came with the gun) floorplate blew off and dumped all the shells on the ground. The bottom of the mag around the floorplate definitely expanded it looks like. The mag is shot I think, but the more important question is how to get the extractor unjammed and the bolt unlocked? I have done everything the owners manual says to do, but I am not sure I want to mess with it any further because I know there is round in the chamber, live or spent I am not sure. The charging handled moves about an inch back and no more! I went ahead and separated the upper from the lower as I could not get the selector back on safe, and I felt a little more comfortable driving it home like that. Bear in the mind this gun is only a few weeks old, been shot once before this, about 30 rounds. After that, I broke it down and cleaned the bolt/lubed. I am pretty frustrated right now, and I am thinking I am going to take it back to the shop where I got it and see if they have any ideas. Any help would be appreciated! I am a little timid to mess with it with a potential live round in the chamber. Also, I have not done any permanent damage have I? |
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First off suspect round in chamber has been fired (safe). Will make no guess as to what has actually occurred as you made NO mention of what type/brand or reloads you were shooting. (hope you were not shooting reloads in a new rifle) For the hang-up problem, (best to have two sets of hands): Re-assemble rifle, place butt-stock on solid ground. Using your left hand on the charging handle release, activate release and place the end of "wooden" hammer handle on the opposite side of charging handle..... Have wife or friend "whack" the head of the hammer "down-ward" to snatch what is left of the round in the chamber out, or "if" it rips the rim off the cartridge, then "lock" bolt and carrier to the rear and use a broke-case extractor to remove remains of the cartridge. Hope this is of some help. BTW, what rounds were you shooting when this happened? Mike |
| I was not shooting reloads. I was shooting some of the 40-pack Winchester value pack 45 grain HPs. I usually use Q3131A, but at this particular moment I was shooting those Winchesters, which had worked fine about 5 minutes before, went through 20 of them no problem. Thanks for the help. |
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While I shoot the Winny value paks on occassions, I TRY to shoot them only in my M4 upper'd ARs. The Winny 45grn. HPs have a sharp open tip and are sometimes more apt to suffer a set-back than say FMJ M193 rounds. Hence the reason for "ramped" uppers with all non-FMJ ammunition on my part. Non-M4 ramped uppers have a dreadful habit (especially for those who believe in cramming ever round possible into their un-tested magazines, which I never do even in my "tested" mags) of nose-diving the top round into the barrel extension. Generally a re-cycling of the charging handle will chamber the round, but if you remove that round and compare it, alot of the time you'll find that the bullet has been "set-back" into the neck of the brass. Sometimes a small amount sometimes alot, depending on the neck tension of that particular lot of ammunition. This fact in combination with a "new" tight rifle can be hazardous A small amout of "set-back" can be fired with no more than a "wow, that round felt hot" comment but a serious "set-back" condition can destroy your rifle. Let us know if this appears to have been the culprit in this case. Here's my Wilson's un-written rule of new AR15 breakin: Never fire anything but accepted "good quality" M193 55grn. FMJ rounds in your new rifle for atleast the first 200 rounds until the rifle is loosened up. They should be cannelured and mil-spec IMO as new AR15s can be tight when they come from the factory. Mike |
| Thanks Mike. I am about to head to the shop and see what they say. I did notice those Winny HPs have the sharp open tip, as opposed to a hole in the tip like some other HPs. Hopefully, I did not permanently screw something up on my brand new gun :(. I will continue to shoot Q3131A as it has worked great thus far. |
| I just got back from the shop, and the gunsmith fixed it in about 5 minutes. He took a punch and hammered back the bolt I guess, then replaced the bent extractor. The shell was spent and blown out on one side. Since it was spent, I could not tell if the bullet was "setback" into the shell or not. Kinda' sucks, I spent $45 and probably lost a mag too. Oh well, at least it is fixed I guess. I just hope I didn't do anything to negatively effect performance or accuracy down the road. He did fire it twice and it worked fine so I guess it is ready to go. |
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Great news there TTUFIN, glad to hear that's all that was damaged. Think your wise to stick with the Q3131A till she loosens up abit. Give some thought to downloading your USGI 20 rounders (18 rnds. is all I ever load of the non-FMJ rounds I test and I never trust those PC mags from Colt, Bushy or anyone) when ya decide to go back to the value-paks and I suspect you'll have no problem after rifle gets broken in...... Mike |
Mike, Hate to play devils advocate but always assume that the round in the chamber is live. A way to tell if you have a live round is just slowly insert a cleaning rod, mark the rod where it bottoms out (at the muzzle). Then using the marked rod, check the rod against the outside of the barrel to see how far down the barrel it went. If the end of the rod (using the muzzle marked section against the muzzle) clears past the delta ring, then the round may have been shot. The reason that I use the term "May" is because the bullet (tip) may be pushed back in the case, with the rod end just moving the bullet/powder out of the way to make it down to the case base web. Also, I’m not a big fan of cramming rods down the bore until you have butt stroked/charging handle pulled to clear the bolt/round. If, and only then, the bolt extractor loses it grip on the rim (the bolt comes back with out the case, then it's time to rod check the round to see if its live or not. If the round is spent, then the rod down the bore to knock the round loose is fine. If you have a live round, then things get a little more tense. |
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