M1 Carbine Broken Bolt

[John Galt]

http://s1254.photobucket.com/user/cabogene/media/photo202.jpg.html
My grandson has an Inland carbine serial # 202xxx that just had the bolt crack next to the extractor. As he is in Calif right now I don't have the bolt or rifle but I am inserting a picture of the crack. I will get the rifle next week and pull it out. I had put new parts in the bolt myself a year or so ago and there was no problem. To my knowledge he was not shooting reloads but old carbine ammo. Any opinions or comments on this and also does anyone have a bolt?

[budster]

Metal Fatigue, possibly?

[kcw]

If the they break, that's where it usually happens. There's a number of them on E-bay. Gun Parts Corp has used ones, complete assembles $90-$170 depending on make. Stripped $65-$95.

[Tuna]

That is where the weakest point is on a carbine bolt. The type 2 flat bolt was an attempt to add some more beef at the extractor to help
prevent breakage and while they are an improvement there are still some that do break.

[John Galt]

Update: Got a new bolt already and thanks for comments. Much appreciated!

[Johnny in Texas]

I had a bolt failure 20 years ago shooting cast bullet reloads. I would bet it was a partially out of battery discharge when mine cracked. it chipped the corner of the right lug lock area of the receiver.

[John Sukey]

Had the same thing happen to an M1 rifle bolt in the same place. Fortunately before I fired it. Was assembling a rifle and took the bolt to the NDI shop, they magnafluxed it and found the crack. Got a freebie from our unit armorer to replace it.

[Art]

Metal Fatigue, possibly?

I would say metal fatigue probably. This sort of possibility is the reason I don't "push" old milsurp rifles. Everything has a use life, including things made out of steel. Even a receiver can only be re used so many times.

[Johnny in Texas]

The bolt, firing pin and the extractor are the weakest links on the M1 Carbine next would be the gas piston housing and the slide spring. IMHO Every carbine shooter should have a spare complete bolt.

[albert]

John, Next time you might want to paste the IMG link from photobucket and your picture will appear in post.

[Gary D. Funderburg]

I have a comment on the broken bolt.
The problem is caused by a bad recoil spring and or poor lubrication. The carbine will fire out of battery. If you look at the front bottom of receiver there will be a white line on receiver and a line on the back of bolt where the bolt is hitting the receiver. What happens when weapon is fired is the slide hits receiver and recoil spring does not have enough power to get the bolt back in battery and it recoils with no hesitation, cracks a bolt or jerks the ear completely off. I have had both happen. " But I am very careful to clean and oil my Carbine" I hear that all the time. Carbine runs on Grease not oil. Good rule of thumb is if it rotates oil it, if it slides Grease it. For those of you that thinks I am wrong? Take your favorite carbine out to the range load it up, pull the slide back about one half inch and fire it. Anyone wants to tell me how wrong I am email me at garys615@aol.com

[George in NH]

If memory serves me correctly (I am at work and my FM's are at home) the Carbine Field Manual describes "oil" for treating the moving parts of the carbine. I have been using "Slip 2000" on my carbine and it seems to stay where I apply it. George in NH

[Litt'le Lee]

if you read futher it describes using grease for parts that wear heavy as also 3 or 4 oils including motor oil--FM23-7-jan52

[Tuna]

Gary, Everything you stated is so very true but it's not the only thing that can cause bolts to let go. If a burr does develop on the receiver where the left bolt lug sits it can cause the bolt not to close properly and then cause the bolt to break when fired. This happens with a lot of the type 3 bolts letting go. But then there are type 2 bolts that also break and they have been closed when fired. The military was well aware of this problem which did lead to the type 2 bolt replacing they type 1 and later the type 3 bolt. There is a lot of stress on the bolt when a round is fired and that can cause the weakest point of the bolt to start to let go at the extractor. But again your right about a properly cleaned and lubed carbine preventing a lot of problems.