So the border patrol is removing Firearms from it's Agents! Woo Hoo Obama Administration!!!

[Krupski]

Disregarding that the article said, AR15/M16/M4 bolts can fail, but it is not usually firing pin related:




The above came from one of my rifles.

On the other hand, I am wondering if they were given a bad batch of firing pins, as in not made to spec?

The rear end of that bolt looks like it was really overheated. The metal has blue and tan coloration. Was the break area smooth or "grainy" looking? If it looked grainy that probably means the steel was too hard (or not tempered enough after heat treat).

Also, the fact that the rear end of the bolt looks overheated shouldn't have anything to do with the breakage. Getting the metal that hot would soften it and make it LESS likely to crack.

[rshaneck2002]

As a ex vet who was trained as a 45B20 (small arms repairman) in the 704th Maint Batt in 1970 this smells to high heaven. Firing pin? really? This is 1st or 2nd area of maint which means the user (soldier) or at the most the unit armorer, 2 minute job at most. There we're 5 ranks of maint when I was in from the man in the field to depot maint which was civilians at the 4th and 5th level. This smells, it is part of a bigger agenda under Obama's homeland security agenda, which means basically no homeland security on our southern border to speak of. Disarming these men and women is tantamount to a crime. The cartels are armed to the teeth. In my 3 yrs (which included combat) I never seen a bolt sear as the one above., my guess, reload loaded far to heavy, or a very bad factory defect. I would like to know who made the bolt in above picture, so I never ever buy one.

[NAPOTS]

I was taught to remove the firing pin every time the rifle is cleaned. If the end user cannot replace the firing pin then IMHO he is not qualified to use the weapon.

[FunkyPertwee]

The rear end of that bolt looks like it was really overheated. The metal has blue and tan coloration. Was the break area smooth or "grainy" looking? If it looked grainy that probably means the steel was too hard (or not tempered enough after heat treat).

Also, the fact that the rear end of the bolt looks overheated shouldn't have anything to do with the breakage. Getting the metal that hot would soften it and make it LESS likely to crack.

What if it had been repeatedly heated up and allowed to cool? Would that harden it and make it brittle?

[5.56NATO]

As a ex vet who was trained as a 45B20 (small arms repairman) in the 704th Maint Batt in 1970 this smells to high heaven. Firing pin? really? This is 1st or 2nd area of maint which means the user (soldier) or at the most the unit armorer, 2 minute job at most. There we're 5 ranks of maint when I was in from the man in the field to depot maint which was civilians at the 4th and 5th level. This smells, it is part of a bigger agenda under Obama's homeland security agenda, which means basically no homeland security on our southern border to speak of. Disarming these men and women is tantamount to a crime. The cartels are armed to the teeth. In my 3 yrs (which included combat) I never seen a bolt sear as the one above., my guess, reload loaded far to heavy, or a very bad factory defect. I would like to know who made the bolt in above picture, so I never ever buy one.

There has always been an issue with carbine ars and full auto use makes it worse. The original 20in ar was designed such that the gas charge unlocked the bolt after the case had contracted back from the chamber wall. The carbines issue is directly related to the length of the gas tube wich is about half or less than the gas tube on a 20in model. Carbines have some issue with extraction, wich results in pulled case heads or rims, broken bolts and firing pins, all sorts of issues stem from the basic carbine design. So instead of addressing the basic flaw, "d rings" and heavier buffers are employed as a bandaid. If there was a way to delay the gas until the case relaxed there'd be less issues with broken parts.

But we all know that 0bama is doing this to to place bp at greater risk.
Just like he had guns run to the cartels and got a bp agent murdered by those same guns.

[imanaknut]

Funny about that photo, as I have the bolt in hand, and the rear of the bolt is not as blue as the photo makes it look. Even cameras seem to be anti-firearm as I have seen many photos of Chinese AK variants with all 4 pieces of wood looking a different color, yet the actual rifle to the human eye all parts match perfectly. Go figure.

As for the rifle it came from, it was a Carbon 15 that was bought second hand, so I don't know much about the first owner, but I ran several thousand rounds of Sellier & Bellot through it before the failure. Back in the days when S&B was available and reasonably priced ($160/1000 rds or less) I bought it by the ton and had great reliability and accuracy through all my .223 rifles. Was really surprised, and later angry when the bolt broke as Bushmaster bought up Professional Ordnance and the bolt turned out to be proprietary that Bushmaster refused to continue making, but they did offer a several hundred dollar upgrade to the old Pro-Ord rifle to use standard bolts.

I am not usually a "tin-hat" person but the way King Barack hates this country I would not be surprised to find there is nothing wrong with any of the rifles taken out of service. Arm drug cartels (the "enemy") and disarm our "well regulated militia, being necessary to the security of a free state" seems to be a mode of operations of the current regime.

[Krupski]

What if it had been repeatedly heated up and allowed to cool? Would that harden it and make it brittle?

Usually, when steel is heated, then cooled quickly, it hardens. But if you heat it and cool it slowly, that tends to soften it.

Tools that are heat treated are typically heated to a dull to bright red, then cooled quickly (quenched) in water or oil. At this point, the metal is very hard and brittle (would shatter if used as a tool).

The next step is "tempering" or "drawing out" where the part is heated again to a much lower temperature (around 350 to 550 degrees F) to soften it a bit (move it away from "brittle" and towards "hard and tough").

Depending on the type of steel, the tempering process leaves the metal either a tan or a blue color.

Anyway, getting to the point... if the rear end of the bolt was getting so hot that it discolored, it most likely would not cool fast enough to make it hard and brittle. I think the metal would tend to soften.

Besides, the bolt in the picture is cracked where the cam pin goes through. The effects of the heat at the rear end of the bolt probably didn't reach up as far forward as the cam pin.

Speaking of cracks and cam pins, everyone who owns an AR-15 should carefully inspect the cam pin AND the bolt for cracks during every cleaning session. After cleaning, look over the cam pin and the bolt carefully with a bright light and a magnifying glass. The cam pin is what limits the rearward travel of the bolt carrier. A cracked cam pin (or if you forget to put it back in) can cause the bolt carrier to be blown out the back end of the stock. In fact, this happened at the indoor range I used to go to. The owner rented out an AR-15 that he had cleaned (but forgot to put the cam pin back in). First shot and the rifle came apart in the guys hands.

Luckily the buffer tube absorbed most of the energy before it was ripped off the receiver (the threads in the aluminum sheared off and were stuck in the threads of the buffer tube).

Thankfully, the customer didn't get hurt and didn't sue the range... but it scared the crap out of everyone there.

[Krupski]

I am not usually a "tin-hat" person but the way King Barack hates this country I would not be surprised to find there is nothing wrong with any of the rifles taken out of service. Arm drug cartels (the "enemy") and disarm our "well regulated militia, being necessary to the security of a free state" seems to be a mode of operations of the current regime.

There's nothing "tinfoil hat" about assuming that 0bama's intentions are the worst. We all know there's nothing wrong with those rifles other than 0bama hates them (and America).

[FunkyPertwee]

Usually, when steel is heated, then cooled quickly, it hardens. But if you heat it and cool it slowly, that tends to soften it.

Tools that are heat treated are typically heated to a dull to bright red, then cooled quickly (quenched) in water or oil. At this point, the metal is very hard and brittle (would shatter if used as a tool).

The next step is "tempering" or "drawing out" where the part is heated again to a much lower temperature (around 350 to 550 degrees F) to soften it a bit (move it away from "brittle" and towards "hard and tough").

Depending on the type of steel, the tempering process leaves the metal either a tan or a blue color.

Anyway, getting to the point... if the rear end of the bolt was getting so hot that it discolored, it most likely would not cool fast enough to make it hard and brittle. I think the metal would tend to soften.

Besides, the bolt in the picture is cracked where the cam pin goes through. The effects of the heat at the rear end of the bolt probably didn't reach up as far forward as the cam pin.

Speaking of cracks and cam pins, everyone who owns an AR-15 should carefully inspect the cam pin AND the bolt for cracks during every cleaning session. After cleaning, look over the cam pin and the bolt carefully with a bright light and a magnifying glass. The cam pin is what limits the rearward travel of the bolt carrier. A cracked cam pin (or if you forget to put it back in) can cause the bolt carrier to be blown out the back end of the stock. In fact, this happened at the indoor range I used to go to. The owner rented out an AR-15 that he had cleaned (but forgot to put the cam pin back in). First shot and the rifle came apart in the guys hands.

Luckily the buffer tube absorbed most of the energy before it was ripped off the receiver (the threads in the aluminum sheared off and were stuck in the threads of the buffer tube).

Thankfully, the customer didn't get hurt and didn't sue the range... but it scared the crap out of everyone there.

Thanks for the science lesson. Thats exactly what I was looking for.

[Hobe Sound AK]

I love how every time I bring up the Idea that we may be headed for a Second Civil War along Racial Line's, everyone say's it can't happen. Look at what happed after the Rodney King Event. Black's Rioted and attacked White Driver's, pulled a Guy out of his Semi, and started beating on him. I recall seeing on the News, a Black Thug had beat a White Man, knocked him out, pulled down his Pant's and Spray Painted His Ball's Black. While the Stupid CNN Camera Man just stood there and Filmed it. When it happens every Minority will come after White Americans. the Advantage is we know how to use our Sights!

[FunkyPertwee]

I love how every time I bring up the Idea that we may be headed for a Second Civil War along Racial Line's, everyone say's it can't happen. Look at what happed after the Rodney King Event. Black's Rioted and attacked White Driver's, pulled a Guy out of his Semi, and started beating on him. I recall seeing on the News, a Black Thug had beat a White Man, knocked him out, pulled down his Pant's and Spray Painted His Ball's Black. While the Stupid CNN Camera Man just stood there and Filmed it. When it happens every Minority will come after White Americans. the Advantage is we know how to use our Sights!

Old but good:

[weevil]

So isn't normal procedure to replace a broken gun with a working one???

Boy I hope our soldiers won't have to wait for their guns to get back from the shop or is that next?


It's pretty obvious that for cheap labor or something more sinister, the powers that be want the border wide open.

Someone is sending a clear message to the BP agents not to go out of their way to seal it up.

[Partisan1983]

It will be 20 years, in a few months, that I have been into small arms.

Over that course of time, I have witnessed 3 bolt failures and 1 firing pin failure in a AR (all were SA only, and 16" carbines) None of 'em ever reached more than a 5K round count.

Murphy's Law..or, Shit happens...here in MI we like to say, Hey, Flint happens


The BG being disarmed in this way, is a pure political chess move...think about it