That' an excellent question. I noticed on one of the 2007 M14s's I got from Marstar, the stock interfered with the op rod as it reached battery position. It caused the oprod to become tightly jammed in the receiver groove as the wood wedged it into an unnatural position. Took me a while to figure out why the oprod seemed so tight in the groove only at battery. The wood that interferes with it is at a point inside the stock. Insufficient clearance.
Results of a M14S/M305 Kabboom
- Thread starter Savage
- Start date
That' an excellent question. I noticed on one of the 2007 M14s's I got from Marstar, the stock interfered with the op rod as it reached battery position. It caused the oprod to become tightly jammed in the receiver groove as the wood wedged it into an unnatural position. Took me a while to figure out why the oprod seemed so tight in the groove only at battery. The wood that interferes with it is at a point inside the stock. Insufficient clearance.
Depends on how light a powder charge are we talking about ,A case filled 60% or less or a case fill greater than 60% ,The problem with shooting any case that has a reduced [60% or less powder charge] in a Semi Auto you are for all intents and purposes is a crap shoot which favours the house which is not the user .
The problem arises from the fact that a semi auto rifles very nature of operation which is with a single pull of trigger the rifle fires and the casing is ejected and a new cartridge is forcefully loaded into the chamber.This is where a reduce powder charge can cause a Catastrophic Failure when the cartridge is is forced into the chamber at st speed the action stops moving forward but your powder charge does not it continues moving forward till all of its energy is spent . In the case of a significantly reduced charge it will leave the primer flash hole exposed and the majority of the powder charge will be located at the base of the projectile. When the rifle is fired the primer will ignite the powder which is OK but not in significantly reduced charges the flame front travels over the exposed exposed powder and then burns the powder this is commonly referred to Flash Over,
Flash Over is the single leading cause of Kabooms in rifles using Factory Ammunition as well a reloaded ammunition .The reduced charge causes extremely high pressure to develop well past the proofing cartridges and well past the design of the firearm to with stand.How does this happen ?.
The most simplest method of explanation is a pop or water bottle filled with water or your favorite beverage , the bottle best resembles the cartridge .When full simply lay the bottle on its side with the bottle still capped you will notice that there is very little air space in the bottle at the top this when a cartridge with the proper powder will perform best . Now reduce the volume of water let's say 25% this is marginally acceptable but you will notice if an increase of air volume this translates into increased pressure at the point of combustion some tell tale signs of this can be found on your brass casing primers unseating themselve or flattened primers. Now reduce the volume another 10% you will notice an even greater increase in air volume this is now fast approaching extreme danger levels the case will exhibit blown and flattened primers and a catastrophic failure is imminent . Any reduction past this point is a recipe for disaster and serious personal injury .Now reduce the volume of the water another 10% place your bottle on its side and lift the rear of the bottle about 1/2" where does all the water run to the front of the bottle this is were the powder will be placed when the casing loaded into the rifle, Now it is easier to understand. The problem occurs when the primer is exposed ,when the primer ignites the flame front races forward igniting the powder in path it is wild fire out of control and consumes all the powder at once this pressure build up is so fast that the projectile cannot leave the barrel fast enough and the resulting pressure spike will cause a catastrophic failure a Ka BOOM.
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No I thought the same thing at first but after careful examination of all the statements and events leading up to the failure I am with out a doubt that this was not a contributing factor .
I too noticed the same issue on mine I simply burned the Chu wood stock and bought a USGI from powmia56
So basically, after firing the 39th shot, the bolt sat in an only partially closed position, not fully rotated clockwise. Its speculated that it could not close all the way owing to the cartridge case not being properly sized over its full length. He pulled the trigger, the hammer dropped on the firing pin, the pin should have been blocked by the design had it worked properly, but instead the gun fired. So no slam fire, just a deliberate firing, but on a partially closed bolt.
Savage,
What is the best way to determine if a out of battery is possible? Is it just a matter of holding the bolt back a little with one's thumb, then seeing if it will pop a primed case?
Would this condition be considered common, rare or freakish and would it affect the originals as well?
There are a pile of M14 owners here, if there is a simple check that they can do to rule out this possibility it be worth while. If others turn up, then that's significant too. Call it my peace of mind poll.
What is the best way to determine if a out of battery is possible? Is it just a matter of holding the bolt back a little with one's thumb, then seeing if it will pop a primed case?
Would this condition be considered common, rare or freakish and would it affect the originals as well?
There are a pile of M14 owners here, if there is a simple check that they can do to rule out this possibility it be worth while. If others turn up, then that's significant too. Call it my peace of mind poll.
To answer your question specifically. The M 14 firing pin is free floating ie it is not contrained by a spring like you find in semi-auto pistols and sporting rifles. I am sure sombody must make a spring for the rifle but in it's out of box configuration the firing pin is free floating. Case gets stuck as it is chambering, forward motion of the bolt stops but the firing pin keeps moving until it reachs the primer and you have what happened here.
You must fully resize your cases for this rifle (the SKS firing pin is freefloating as well) or you run the risk of an out of battery firing.
Take Care
Bob
Grizzlypeg,
You have it exactly right, except that it was the 39th cartrige that let go. I can say that I ran the first 10 cartridges through the magazine and chamber to verify the die settings, before I loaded the next 40 which I didn't check.
Bob, I'm not sure I agree. You say the forward motion of the bolt stops but the firing pin keeps moving. I don't believe that is what happened here. If that was what happened, he would have pulled the trigger and hear two shots. The firing pin, if I understand it right, got driven into the primer by the hammer following a deliberate trigger pull. Correct? What went wrong if I read Savage correctly, is that the bolt was stationary, and could have been so for any period of time and this could have happened, its just that it wasn't fully closed.
Savage,
What is the best way to determine if a out of battery is possible? Is it just a matter of holding the bolt back a little with one's thumb, then seeing if it will pop a primed case?
Would this condition be considered common, rare or freakish and would it affect the originals as well?
There are a pile of M14 owners here, if there is a simple check that they can do to rule out this possibility it be worth while. If others turn up, then that's significant too. Call it my peace of mind poll.
I posted a test that one could easily do using Pennies and Dimes to measure the gap
Check this post out http://www.canadiangunnutz.com/forum/showthread.php?t=328091
Dogleg given the fact that there are wide variances in the manufacturing of the Norinco M305 with regards to to the firing pin bridge block the results are rather alarming .
Yes but the trigger won't release the hammer until the bolt is closed fully. I suspect you were shooting fast, as the gun attempted to chamber the next round you puled the trigger. The out of battery firing occured when the bolt stopped, due to the case getting stuck in the chamber, and the firing pin continued on and hit the primer.
If I hold the bolt half open after cocking my M 14, pulling the trigger does nothing. It will only release the hammer when the bolt is closed. The gun is designed that way for obvious reasons.
This is the reason why reloaders are told to fully resize cases that are to be shot in this style of gun.
Take Care
Bob
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Yes BUT the firing pin on these guns is free floating. It is not restrained by a firing pin spring. What happened here can happen any time a case gets stuck as it is getting seated. It may not happen every time but it will happen. If you do a search I am sure there are after market suppliers who make a spring for the firing pin for this rifle. I know they are available for the SKS. The fact you have a firing pin spring won't guarantee it won't happen but it will reduce the possibility down to close to zero. If semi auto pistols were made this way ie without a firing pin spring out of battery firings would make the design useless.
Take Care
Bob
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punkrockboy
CGN Ultra frequent flyer
- Location
- Eastern Bantario!
This can cause slam-fire, out of battery fire, etc, but Doglegs gun blew up in the coarse of a deliberate trigger pull. So if the bolt wasnt full seated, the hammer should not have released in the first place, no?
Canuck44,
It was the last shot in the magazine. As you say the weapon is designed to prevent firing when the bolt is not fully closed, that is the point. The design, or the execution of the design failed failed to prevent that occurance. Savage has already proven that mine can and did.
It was the last shot in the magazine. As you say the weapon is designed to prevent firing when the bolt is not fully closed, that is the point. The design, or the execution of the design failed failed to prevent that occurance. Savage has already proven that mine can and did.
Bob you need to re read this or get a better understanding on how the rifle operates and its inherent safety features work it is a case of out of battery firing .The firing pin does not have enough inertia /energy to fire the cartridge by it self that's why when you pull the trigger the hammer hits the firing pin setting off the cartridge
However the hammer will strike the firing pin before completely in battery the reason which might not be clear is that this rifle uses a rotating locking lug to achieve Battery or Lock up. The locking lugs are not square but rather tapered on the rear to achieve proper fitment if the bolt were to lift up say .115" the bolts reward movement is only .005-.010 it also affects the head spacing as well ,the Hammer will strike the firing pin every time . because the bolt is in the position to fire
this part I agree with
Bob
The firing pin simply lacks the inertia to strike with enough force to set off the primer as for the after market conversion kit let me know when you find one for the M14 style rifles
bclinehand
CGN frequent flyer
- Location
- Clearwater B.C.
I agree with this statement
except
I believe this incident was caused by a combination of the improperly sized case not being able to enter the chamber as well as the extremely cold temperature the firearm was being fired in causing the lubricant to sieze up and the firing pin stick in the forward position either because the pin itself siezed or something in the trigger group siezed
"The firing pin does not have enough inertia /energy to fire the cartridge by it self that's why when you pull the trigger the hammer hits the firing pin setting off the cartridge"
I just took a empty deprimed 30-06 case and inserted a plastic insert, designed for dry firing pistols, into the primer pocket. I then inserted the .30-06 case into the chamber of my M 14. The case protrudes about a half inch.
I the dropped the bolt and there is a clearly fully indent where the firing pin hit the insert. It was a ful indent not just a small pin mark. I know the firing pin is designed not to have enough inertia to cause ignition when the case fully chambers and in most cases it probably doesn't have enough inertia to fire them off when out of battery BUT given soft primers or a primer not seated properly and you have the makings for an out of battery firing caused from the free floating firing pin. To test this further once the weather improves I will take an unloaded .30-06 case with a Win primer seated and do the test at the range.
When events like this happen it usually isn't just one thing that creats the problem but a series of events that normally don't present a problem by themselves but when they all come to gether you get an unexpected bang when all should have been quiet.
Take Care
Bob
Take Care
Bob
I just took a empty deprimed 30-06 case and inserted a plastic insert, designed for dry firing pistols, into the primer pocket. I then inserted the .30-06 case into the chamber of my M 14. The case protrudes about a half inch.
I the dropped the bolt and there is a clearly fully indent where the firing pin hit the insert. It was a ful indent not just a small pin mark. I know the firing pin is designed not to have enough inertia to cause ignition when the case fully chambers and in most cases it probably doesn't have enough inertia to fire them off when out of battery BUT given soft primers or a primer not seated properly and you have the makings for an out of battery firing caused from the free floating firing pin. To test this further once the weather improves I will take an unloaded .30-06 case with a Win primer seated and do the test at the range.
When events like this happen it usually isn't just one thing that creats the problem but a series of events that normally don't present a problem by themselves but when they all come to gether you get an unexpected bang when all should have been quiet.
Take Care
Bob
Take Care
Bob
