lamarbrog
27 August 2011, 15:52
Recently I've been getting serious about practicing how to clear malfunctions. I've found this whole topic to be very stressful, because of inconsistencies in the naming of the various malfunctions, and my inability to comprehend any way how half of these malfunctions could ever feasibly occur.
Since this forum has the highest concentration of knowledgeable people I've encountered, I figure y'all can probably set me straight and get me back on my merry way. So, what I'm going to do is list what I currently think I know... then anyone who cares to can correct it.
Double Feed
Two live rounds attempting to enter the chamber at the same time.
Caused by operator error, riding the charging handle most of the way forward, then retracting it and releasing it again. Or, caused by a magazine with worn feed lips, or a weak spring.
Cleared by forcibly removing the magazine, retracting the charging handle, and shaking the rounds free. If one is in the chamber, and the other is behind it, the extractor should be used to remove this round if it did not shake loose freely.
Failure to Unlock
A spent casing is stuck in the chamber, and the bolt is still latched onto it.
Caused by a tight, hot, or dirty chamber. Or, out of spec ammunition. Or, a failure of the gas system.
Cleared by pulling back on the charging handle while firmly striking the butt of the rifle against the ground or a wall. (Contrary to popular belief, I've done this dozens of times when working at a range that rented full autos, and never once broke the stock of a rifle.)
Failure to Extract
A spent casing is stuck in the chamber, and the bolt has forced another round up behind it during cycling.
Caused by a tight, hot, or dirty chamber. Or, out of spec ammunition. Or, a failure of the gas system. Or, damage to the extractor. Or, a flaw in the casing.
Cleared by dropping the magazine, and dropping the bolt onto the casing. Attempt to extract the casing by hand. If the charging handle moves the bolt, but the casing stays put, knock it free with a cleaning rod. If the bolt latches on, but you're unable to extract by hand, follow the procedure for the Failure to Unlock.
Failure to Eject
A spent casing is stuck partially out of the ejection port.
Caused by ejection port obstruction, or just by freak chance.
Drop the magazine. Retract the charging handle. Release the charging handle. Retract the charging handle, extracting and ejecting the live round. Release charging handle. Insert magazine, charge the rifle.
Failure to Feed
A round is attempting to enter the chamber but has failed to do so.
Caused most commonly by riding the charging handle forward. Or, a weak action spring. Or, using grease in cold weather.
Hit the forward assist.
Bolt Override
The bolt has cycled enough to eject the spent casing, but did not pick up a new round from the magazine resulting in an empty chamber.
Caused by short-cycling. Or, a weak magazine spring/damaged magazine body.
Charge the rifle.
Brass Over Bolt
A spent casing has failed to eject, and has become lodged between the bolt carrier/gas key and the charging handle. The bolt is in the process of attempting to feed a new round.
Caused by an issue with the ejector or by an ejection port obstruction.
Forcibly remove the magazine. Use the middle finger of the right hand to put force on the bolt through the magazine well while pulling back on the charging handle. After moving the bolt back a half inch or so, force the charging handle forward, allowing the casing to drop free.
The main issue I have is with "Bolt Override". It seems people use that as a description of what I call a "Brass Over Bolt". I can't figure out how "Bolt Override" describes that event at all.... the bolt did not "override" anything... the brass just got caught above the bolt during a failure to eject.
I've also heard of this thing called a "Triple Feed", which appears to be a combination of what I refer to as a "Brass Over Bolt" and a Double Feed. I can't see any way this would happen aside from the rifle double-feeding from a defective magazine at the same time it had a failure to eject. ... Realistically, what are the chances of that ever happening? I guess it is definitely mechanically possible... but if it does happen I'm going to start playing the lottery. Has anyone ever actually experienced this? Care to chime in with the cause?
This so-called "Triple Feed" also appears to be referred to as a "Charging Handle Impingement". Now, that name I could see as being a good term for what I call a "Brass Over Bolt", except I'd use the term "Charging Handle Impediment".
Maybe I'm the only person bothered by this... but it seems to me training people to solve these problems would be much easier if there was actually consistent naming that described accurately what the problem is.
Since this forum has the highest concentration of knowledgeable people I've encountered, I figure y'all can probably set me straight and get me back on my merry way. So, what I'm going to do is list what I currently think I know... then anyone who cares to can correct it.
Double Feed
Two live rounds attempting to enter the chamber at the same time.
Caused by operator error, riding the charging handle most of the way forward, then retracting it and releasing it again. Or, caused by a magazine with worn feed lips, or a weak spring.
Cleared by forcibly removing the magazine, retracting the charging handle, and shaking the rounds free. If one is in the chamber, and the other is behind it, the extractor should be used to remove this round if it did not shake loose freely.
Failure to Unlock
A spent casing is stuck in the chamber, and the bolt is still latched onto it.
Caused by a tight, hot, or dirty chamber. Or, out of spec ammunition. Or, a failure of the gas system.
Cleared by pulling back on the charging handle while firmly striking the butt of the rifle against the ground or a wall. (Contrary to popular belief, I've done this dozens of times when working at a range that rented full autos, and never once broke the stock of a rifle.)
Failure to Extract
A spent casing is stuck in the chamber, and the bolt has forced another round up behind it during cycling.
Caused by a tight, hot, or dirty chamber. Or, out of spec ammunition. Or, a failure of the gas system. Or, damage to the extractor. Or, a flaw in the casing.
Cleared by dropping the magazine, and dropping the bolt onto the casing. Attempt to extract the casing by hand. If the charging handle moves the bolt, but the casing stays put, knock it free with a cleaning rod. If the bolt latches on, but you're unable to extract by hand, follow the procedure for the Failure to Unlock.
Failure to Eject
A spent casing is stuck partially out of the ejection port.
Caused by ejection port obstruction, or just by freak chance.
Drop the magazine. Retract the charging handle. Release the charging handle. Retract the charging handle, extracting and ejecting the live round. Release charging handle. Insert magazine, charge the rifle.
Failure to Feed
A round is attempting to enter the chamber but has failed to do so.
Caused most commonly by riding the charging handle forward. Or, a weak action spring. Or, using grease in cold weather.
Hit the forward assist.
Bolt Override
The bolt has cycled enough to eject the spent casing, but did not pick up a new round from the magazine resulting in an empty chamber.
Caused by short-cycling. Or, a weak magazine spring/damaged magazine body.
Charge the rifle.
Brass Over Bolt
A spent casing has failed to eject, and has become lodged between the bolt carrier/gas key and the charging handle. The bolt is in the process of attempting to feed a new round.
Caused by an issue with the ejector or by an ejection port obstruction.
Forcibly remove the magazine. Use the middle finger of the right hand to put force on the bolt through the magazine well while pulling back on the charging handle. After moving the bolt back a half inch or so, force the charging handle forward, allowing the casing to drop free.
The main issue I have is with "Bolt Override". It seems people use that as a description of what I call a "Brass Over Bolt". I can't figure out how "Bolt Override" describes that event at all.... the bolt did not "override" anything... the brass just got caught above the bolt during a failure to eject.
I've also heard of this thing called a "Triple Feed", which appears to be a combination of what I refer to as a "Brass Over Bolt" and a Double Feed. I can't see any way this would happen aside from the rifle double-feeding from a defective magazine at the same time it had a failure to eject. ... Realistically, what are the chances of that ever happening? I guess it is definitely mechanically possible... but if it does happen I'm going to start playing the lottery. Has anyone ever actually experienced this? Care to chime in with the cause?
This so-called "Triple Feed" also appears to be referred to as a "Charging Handle Impingement". Now, that name I could see as being a good term for what I call a "Brass Over Bolt", except I'd use the term "Charging Handle Impediment".
Maybe I'm the only person bothered by this... but it seems to me training people to solve these problems would be much easier if there was actually consistent naming that described accurately what the problem is.