The original carbines  were milled with a flat area on top of the bolt.  In WW2 they were not that much of a problem but in Korea they were.  The guy that trained me at Picatinny told me his brother helped put about 18 dead GIs in body bags after a battle in sub zero temperatures when the bolts failed, blew out and the bolt parts went into foreheads killing them.  This happened when I was at the Federal Law Enforcement Training center in 80s when a trainee had one fail and was taken to infirmary with blood streaming from his forehead and the safety office saw him and  I conducted the investigation and was asked to submit recommendation so this would not happen again.

 

If you have and are wanting to shoot a M1 carbine you need to get a M2 round body bolt as they are much stronger.  If you are a reloader stay away from max loads.

On the one you saw in your investigation, what part of the bolt failed? 

I call BS.  

M1 Carbine and M1 rifle bolts fail at locking lugs not just crack in half and kill the shooter.  The “I knew a guy who had a brother” is not proof of anything.  Mighty bold claims.  

On 9/9/2023 at 7:34 AM, Hummer said:

The original carbines  were milled with a flat area on top of the bolt.  In WW2 they were not that much of a problem but in Korea they were.  The guy that trained me at Picatinny told me his brother helped put about 18 dead GIs in body bags after a battle in sub zero temperatures when the bolts failed, blew out and the bolt parts went into foreheads killing them.  This happened when I was at the Federal Law Enforcement Training center in 80s when a trainee had one fail and was taken to infirmary with blood streaming from his forehead and the safety office saw him and  I conducted the investigation and was asked to submit recommendation so this would not happen again.

 

If you have and are wanting to shoot a M1 carbine you need to get a M2 round body bolt as they are much stronger.  If you are a reloader stay away from max loads.

Are you sure about this? 

I've not heard about any exploding bolts killing people.

I've kicked a bolt out of an M1 Carbine before - it did not kill me (nor hit anywhere near me, nor have the velocity required to go through my thick skull).  I think it had to do with the operating rod not being properly seated after reassembly thus allowing enough wiggle room for the lug to slip past and eject. It was a mixmaster which I sold soon after. 

33 minutes ago, AustinO said:

I've kicked a bolt out of an M1 Carbine before - it did not kill me (nor hit anywhere near me, nor have the velocity required to go through my thick skull).  I think it had to do with the operating rod not being properly seated after reassembly thus allowing enough wiggle room for the lug to slip past and eject. It was a mixmaster which I sold soon after. 

Yeah I had a flat bolt break off at the lug. Nothing catastrophic.

Some folks don't know when they're being fed a story.  However, I thought Hummer could be specific on the failure he investigated and the nature of the investigation.    

On 9/9/2023 at 7:34 AM, Hummer said:

The original carbines  were milled with a flat area on top of the bolt.  In WW2 they were not that much of a problem but in Korea they were.  The guy that trained me at Picatinny told me his brother helped put about 18 dead GIs in body bags after a battle in sub zero temperatures when the bolts failed, blew out and the bolt parts went into foreheads killing them.  This happened when I was at the Federal Law Enforcement Training center in 80s when a trainee had one fail and was taken to infirmary with blood streaming from his forehead and the safety office saw him and  I conducted the investigation and was asked to submit recommendation so this would not happen again.

 

If you have and are wanting to shoot a M1 carbine you need to get a M2 round body bolt as they are much stronger.  If you are a reloader stay away from max loads.

What a load of hogwash.

On 9/9/2023 at 7:34 AM, Hummer said:

The original carbines  were milled with a flat area on top of the bolt.  In WW2 they were not that much of a problem but in Korea they were.  The guy that trained me at Picatinny told me his brother helped put about 18 dead GIs in body bags after a battle in sub zero temperatures when the bolts failed, blew out and the bolt parts went into foreheads killing them.  This happened when I was at the Federal Law Enforcement Training center in 80s when a trainee had one fail and was taken to infirmary with blood streaming from his forehead and the safety office saw him and  I conducted the investigation and was asked to submit recommendation so this would not happen again.

 

If you have and are wanting to shoot a M1 carbine you need to get a M2 round body bolt as they are much stronger.  If you are a reloader stay away from max loads.

Yikes- I’ve been shooting with the flat bolts for 49 years without problems.

 

is it just at very cold temps? 

1 hour ago, blind pew said:

Yikes- I’ve been shooting with the flat bolts for 49 years without problems.

 

is it just at very cold temps? 

My grandfather was very fond of the M1 carbine. He used his in the Battle of the Bulge. I hear it was pretty cold there. 
 

I too have shot quite a few rounds with a flat bolt.   
 

I would love more explanation/personal experience with this before I freak out and stop. Or is this like the self firing Sig P320?

 

I really don’t plan on going shooting when it’s stupid cold anyway. I guess I’m getting softer as I get older. 

1 hour ago, blind pew said:

Yikes- I’ve been shooting with the flat bolts for 49 years without problems.

 

is it just at very cold temps? 

It's a BS story..

Carbine Failures File.zip

Who trained with carbines at FLETC in the 1980’s? 

I was the successful bidder on a CMP carbine years ago.  I cleaned and inspected the carbine and all seemed right.  On the first round fired at the range, the bolt failed at the extractor.  There was nothing catastrophic about this failure.  The second round jammed, and it took a moment to realize what had happened.  But, the bottomline was that this was not some sort of cataclysmic event.  

At FLETC the Bureau of Prisons loved them.  I was asked by Asst Director of FLETC to do a failure analysis on a carbine that let go and gashed a student in the head.  The BOP dumped all their carbines as they had no idea how many rounds had been fired through them.

Finally got picture of blown rifles.

Without context, this does not mean much of anything.

2 hours ago, BryanJ said:

Without context, this does not mean much of anything.

It's well known that the weak point on carbines is the right bolt lug due to all the cuts for the extractor etc in it.

17 hours ago, Hummer said:

Finally got picture of blown rifles.

Broken lugs on both Carbines and M1 rifles is/ was not uncommon at all. What is uncommon is this pronunciation that they are unsafe and will kill anyone using it…”18 after just one battle”. The whole purpose of this pix was Ord Dept emphasizing the need to at least look over your weapon and inspect for cracks before things break.

 This silliness reminds me of the hype the M9 pistol went thru….seems everyone that was in from 1985 to 2016 knew and saw a guy killed by a slide coming off and hitting them in the head.  Death toll must have reached at least 40k killed by those slides…..yet the numbers GAO published is 14 slide failures and 4 injuries.

54 minutes ago, Rhscott said:

Broken lugs on both Carbines and M1 rifles is/ was not uncommon at all. What is uncommon is this pronunciation that they are unsafe and will kill anyone using it…”18 after just one battle”. The whole purpose of this pix was Ord Dept emphasizing the need to at least look over your weapon and inspect for cracks before things break.

 This silliness reminds me of the hype the M9 pistol went thru….seems everyone that was in from 1985 to 2016 knew and saw a guy killed by a slide coming off and hitting them in the head.  Death toll must have reached at least 40k killed by those slides…..yet the numbers GAO published is 14 slide failures and 4 injuries.

Stop making sense....this is the internet and everything needs to be blown out of proportion...

The 1st page of the .pdf in post #12 seems to sum up everything for me. To quote it: The principal causes of accidents and malfunctions of carbines are worn or defective parts, and insufficient lubrication.

 

Any firearm you neglect or continue to use with worn or defective parts and insufficient lubrication is likely to fail, be it an M-1 Carbine, an M-9 pistol, or your bolt action .22 single shot rifle. Just like any other tool you own; you must maintain them if you expect them to do the work they were designed to do.

 

A bit of Urban Legend may have crept into this post but the last sentence of post #1 seems to be more of a recommendation that a condemnation to me. To quote it: If you have and are wanting to shoot a M1 carbine you need to get a M2 round body bolt as they are much stronger.  If you are a reloader stay away from max loads.

 

Both of those seem like sensible things to consider.

 

Hummer. Thank you for providing some pages from that manual.

For those who haven't downloaded the zipped files.

What we are looking at is

  June 1953

Departments of Army and the Air Force

TM9-2210

TO39A-5A-6  

Small Arms Accidents Malfunctions and their Causes

 

Based on that alone I'll say that your conclusion and advice differs from the point being made in the manual.

The manual says -

"resulted from continued firing with a cracked bolt."

 

The next paragraph provides another example of worn or defective parts this time related to the operating slide, and the last paragraph describes the catastrophic failures caused by continuous use without lubrication.  One of which is "right hand locking lug broken"

 

I'll again invite you to help us better understand your investigation, and how you determined the design of the flat bolt rather than the condition and care was the cause.

In particular "On the one you saw in your investigation, what part of the bolt failed? "

 

The Carbine Club has an excellent page on bolt variations and development.

http://www.uscarbinecal30.com/bolts.html

The right lug was strengthened mid 1942.  Of course its still possible to occassionally find a carbine with an earlier bolt, just as early extractors and extractor plugers still show up.

Round bolts are generally going to be better performing but were not considered a required change during overhaul.  Note they still have a hole for the extractor next to the lug and another for extractor plunger and spring that goes into the lug.    Further note that the changes timing work best in conjunction with the matching operating slides, but like most carbine parts they can be used with the older slides regardless.
 

I still wonder how your buddies brother managed to put 18 or so frozen stiff bodies in body bags after they were all killed by breaking bolts. You did say it was sub zero. Bodies freeze and stiffen real quick in freezing temps; the way they fall and not nice and neat to fit in a bag.

This whole discussion has been about BS. 

34 minutes ago, Rhscott said:

 

This whole discussion has been about BS. 

This is the correct answer 

I think everyone knows it was cold in Korea and Im sure bolts broke. And at this point most of these rifles now are 60- 80 years old. So yea

it can happen mostly in the lugs like has been stated.

 

I'm not at all concerned about the issue as I dont own one of these types of rifles and most likely never will.

As far as an instructor relaying a story heard from someone this or that, grain of salt kind of thing.

But, the lack of decorum shown to the original poster is disappointing.

These kind of replies from some above...... are what discourages people from posting.

Its an interesting topic and thank you to the original poster for posting it.