M305 Bolt Failure
- Thread starter watermine
- Start date
So the accurate shooter article writer got the pressures wrong (psi vs cup)? Either way, follow manufacturers load data for 7.62x51 (service rifle), which should keep you safe. Forgot, the military's not bound by SAAMI right. Thanks for the lack of sarcasm 
Since you guys know so much, how about writing your own articles
Wikipedia must be right http://en.wikipedia.org/wiki/7.62%C3%9751mm_NATO
Maximum pressure 415 MPa (60,200 psi)
The 7.62×51mm NATO (official NATO nomenclature 7.62 NATO) is a rifle cartridge developed in the 1950s as a standard for small arms among NATO countries. It should not to be confused with the similarly named Russian 7.62×54mmR cartridge.
It was introduced in U.S. service in the M14 rifle and M60 machine gun in the late 1950s. The M14 was superseded in U.S. service as the infantry adopted the 5.56×45mm NATO M16. However, the M14 and many other firearms that use the 7.62×51 round remain in service, especially in the case of sniper rifles, machine guns, and as the service weapon chosen by special operations forces. The cartridge is used both by infantry and on mounted and crew-served weapons mounted to vehicles, aircraft and ships.
Although not identical, the 7.62×51mm NATO and the commercial .308 Winchester cartridges are similar, and even though the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) considers it safe (by not listing it) to fire the NATO round in weapons chambered for the commercial round, there is significant discussion[3][4][5] about compatible chamber and muzzle pressures between the two cartridges based on powder loads and wall thicknesses on the military vs. commercial rounds. The debate goes both ways, the ATF recommends checking the stamping on the barrel; if you're unsure, consult the maker of the firearm.
Since you guys know so much, how about writing your own articles Wikipedia must be right
http://en.wikipedia.org/wiki/7.62%C3%9751mm_NATOMaximum pressure 415 MPa (60,200 psi)
The 7.62×51mm NATO (official NATO nomenclature 7.62 NATO) is a rifle cartridge developed in the 1950s as a standard for small arms among NATO countries. It should not to be confused with the similarly named Russian 7.62×54mmR cartridge.
It was introduced in U.S. service in the M14 rifle and M60 machine gun in the late 1950s. The M14 was superseded in U.S. service as the infantry adopted the 5.56×45mm NATO M16. However, the M14 and many other firearms that use the 7.62×51 round remain in service, especially in the case of sniper rifles, machine guns, and as the service weapon chosen by special operations forces. The cartridge is used both by infantry and on mounted and crew-served weapons mounted to vehicles, aircraft and ships.
Although not identical, the 7.62×51mm NATO and the commercial .308 Winchester cartridges are similar, and even though the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) considers it safe (by not listing it) to fire the NATO round in weapons chambered for the commercial round, there is significant discussion[3][4][5] about compatible chamber and muzzle pressures between the two cartridges based on powder loads and wall thicknesses on the military vs. commercial rounds. The debate goes both ways, the ATF recommends checking the stamping on the barrel; if you're unsure, consult the maker of the firearm.
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Ardent
CGN Ultra frequent flyer
And Norincos will still be touted in this forum for decades.
This week I've read about:
-Catastrophic bolt failure
-Catastrophic barrel failure
-Razor sharp op rod handles
-Cracked gas cylinder, full length, from the factory before firing
My eyes are worth LRB and Springfield prices. People are going to jump on me, again, but this isn't just a joke, we're putting contained explosions inches from our heads, throats, and hands and trusting Chinese bottom basement crap to contain the 50,000+psi. Support the good guys, they're on our side too, and more than worth the money.
This week I've read about:
-Catastrophic bolt failure
-Catastrophic barrel failure
-Razor sharp op rod handles
-Cracked gas cylinder, full length, from the factory before firing
My eyes are worth LRB and Springfield prices. People are going to jump on me, again, but this isn't just a joke, we're putting contained explosions inches from our heads, throats, and hands and trusting Chinese bottom basement crap to contain the 50,000+psi. Support the good guys, they're on our side too, and more than worth the money.
And Norincos will still be touted in this forum for decades.
This week I've read about:
-Catastrophic bolt failure
-Catastrophic barrel failure
-Razor sharp op rod handles
-Cracked gas cylinder, full length, from the factory before firing
My eyes are worth LRB and Springfield prices. People are going to jump on me, again, but this isn't just a joke, we're putting contained explosions inches from our heads, throats, and hands and trusting Chinese bottom basement crap to contain the 50,000+psi. Support the good guys, they're on our side too, and more than worth the money.
That's only he stuff you hear about... The importers have piles of broken guns in warehouses.
shooterman
CGN Regular
- Location
- S. Ontario
And Norincos will still be touted in this forum for decades.
This week I've read about:
-Catastrophic bolt failure
-Catastrophic barrel failure
-Razor sharp op rod handles
-Cracked gas cylinder, full length, from the factory before firing
My eyes are worth LRB and Springfield prices. People are going to jump on me, again, but this isn't just a joke, we're putting contained explosions inches from our heads, throats, and hands and trusting Chinese bottom basement crap to contain the 50,000+psi. Support the good guys, they're on our side too, and more than worth the money.
You got that right! I can't think of a single product of any quality from china. Why buy this junk when its plagued with so many problems?
Ardent
CGN Ultra frequent flyer
In fairness, my iPhone I write this on is Chinese. They can make quality items, but their guns largely are turds with some components (receivers) of decent quality, but wonky dimensions. Wonky dimensions were my frustration with the M305's I built on when still listening to the "good as USGI" koolaid.
What has really put me off in recent years is the manufacturers of good western gun products aren't usually all that big, especially compared to Norinco. They need our support more and are actually allies, that's reason enough without all the failures. It's only a matter of time until someone gets very seriously hurt or killed with what we're seeing as of late.
When Norinco first started making these M305 clones of the M14 rifle, there were some bolts that weren't heat-treated properly that failed.
I'm no metallurgist, but looking at your bolt, it looks to me like that bolt wasn't properly heat-treated, causing the roller lug to eventually shear off.
The rifle is a mass-produced product, built in a country that is known to have quality-control issues from time to time.
The rifle itself costs $450. If it were me, I'd just buy another one and keep the one that broke the bolt for spares.
You could buy another bolt and have it headspaced by a gunsmith, though.
I'm no metallurgist, but looking at your bolt, it looks to me like that bolt wasn't properly heat-treated, causing the roller lug to eventually shear off.
The rifle is a mass-produced product, built in a country that is known to have quality-control issues from time to time.
The rifle itself costs $450. If it were me, I'd just buy another one and keep the one that broke the bolt for spares.
You could buy another bolt and have it headspaced by a gunsmith, though.
The shame, at least you're man enough to come out of the closet to admit it. Be true to yourself, promise you'll never buy and use another Chinese product. North America or nothing 
Imagine the horror of that iPhone exploding unshielded next to your face, or worst yet in the pocket besides the crown jewels.
Imagine the horror of that iPhone exploding unshielded next to your face, or worst yet in the pocket besides the crown jewels.
And Norincos will still be touted in this forum for decades.
This week I've read about:
-Catastrophic bolt failure
-Catastrophic barrel failure
-Razor sharp op rod handles
-Cracked gas cylinder, full length, from the factory before firing
My eyes are worth LRB and Springfield prices. People are going to jump on me, again, but this isn't just a joke, we're putting contained explosions inches from our heads, throats, and hands and trusting Chinese bottom basement crap to contain the 50,000+psi. Support the good guys, they're on our side too, and more than worth the money.
Years ago I posted on here about it being a good idea for people to check that the receiver bridge that blocks the firing pin is in spec so that the guns won't fire in partial lock or out of battery. Pretty much told by the M14 experts on here to go #### myself as it's not an issue if you FL size or shoot factory ammo. With measured headspace on these things varying 20-30thou from one gun to the next, and all the other sloppy QC issues, I have zero faith that this important safety feature is made to spec and will prevent this from happening.
beavis_m305
Regular
- Location
- New Zealand
From what I have read I am lead to believe that even the US rifles, real M14's and M1A's can and do suffer from some of the same issues (excess head space, safety bridge not really working, slam firing, component failure etc)
Ardent
CGN Ultra frequent flyer
Excellent point
Any semi can share these issues (less the M14 specific), or have their own issues, a lot is going on in a semi. Because a Hyundai Pony could have a crankshaft failure brand new and it happened to a Cummins a few times somewhere does not make them the same quality. The failure rate of an LRB build (close to USGI as it gets) is almost certainly going to be (far) less than one catastrophic failure per hundred Norinco failures, less than 1% as many sort of stuff. So sure, it could happen, and google will show you anything you want to dig for, but for every quality M14 failure I'll show you dozens from Norinco.
In essence, and this is a big problem with the Battle Rifle forum, "what I've read and been lead to believe" sentiment causes great numbers of people to believe their Chinese guns are close to as good (even often touted as better!) as a Springield, LRB, or USGI. They are far, far from it, and reflect their price point completely. People like to think they're getting the bargain of the century and they're in on a secret / know more than those spending a half dozen times as much. Fact is a lot of folks forking out for LRB et al have been turned off by the "bargain" rifles through experience, not what they've read. Some have good luck with Norincos, I wasn't one of them unfortunately.
Now Ardent, you're talking about this like you're sounding that you read a single review with a sharp op rod handle. I thought this was standard spec for Norinco to have razor sharp edges
.Glad you came out of this safely OP. That had to be a butt puckering moment.
Ardent
CGN Ultra frequent flyer
Ha indeed, and me too for the OP being OK. I have a complete Norc bolt I've dug out of the basement from when I built on Norc receivers, used to do a fair bit of it, will send it to him free if he wants so he has a complete rifle at least.
And good lord I know why I'm awake at 05:00 and burning time on CGN, but why you!?
And good lord I know why I'm awake at 05:00 and burning time on CGN, but why you!?
And Norincos will still be touted in this forum for decades.
This week I've read about:
-Catastrophic bolt failure
-Catastrophic barrel failure
-Razor sharp op rod handles
-Cracked gas cylinder, full length, from the factory before firing
My eyes are worth LRB and Springfield prices. People are going to jump on me, again, but this isn't just a joke, we're putting contained explosions inches from our heads, throats, and hands and trusting Chinese bottom basement crap to contain the 50,000+psi. Support the good guys, they're on our side too, and more than worth the money.
Your common sense approach to this issue will make you no friends here.
shooterman
CGN Regular
- Location
- S. Ontario
Very rare. Bad reloads responsible in most cases.
Ardent
CGN Ultra frequent flyer
So I've learned...!
And Norincos will still be touted in this forum for decades.
This week I've read about:
-Catastrophic bolt failure
-Catastrophic barrel failure
-Razor sharp op rod handles
-Cracked gas cylinder, full length, from the factory before firing
My eyes are worth LRB and Springfield prices. People are going to jump on me, again, but this isn't just a joke, we're putting contained explosions inches from our heads, throats, and hands and trusting Chinese bottom basement crap to contain the 50,000+psi. Support the good guys, they're on our side too, and more than worth the money.
WTF is with the razor sharp op rod handles anyway? Bought a used camo version and the op rod handle was a conversation piece. Seriously, they could not possibly miss that and know we have to fix it after purchase. And we are surprised other things go wrong?
With you on that, remember the post. My first won't catch an early firing pin reliably. Don't recall the disagreement but you know your right. When people cannot understand the tech you are explaining give up, they will never understand and it just tortures you.
Also not a metallurgist but the grain structure of the bolt looks course to me. I'd say the casting on that bolt is crap.
