Broken bolt...

[Colter44]

I took my carbine out to do some shooting this weekend for the first time in a few years and the bolt broke. The rifle was shooting fine for about 40 rnds of slow fire before the bolt failure. The bolt broke at the base of the lobe that connects to the op rod. This is the second time this has happened with this rifle. The bolt is USGI. The ammo I am shooting is wolf steel case that I bought from the CMP. I am not sure what's going on, any advice would be great? Thanks.

[jak]

Early production flat bolts were known to break at that area. I would suggest getting
a round bolt. The bugs were worked out by then.

[Colter44]

This was a round bolt that broke. I am not sure really what direction to take on this.

[jak]

I hope you checked head space after replacing the bolt the first time. Also check the slide and receiver for worn spots
or grooves that would prevent the bolt from moving smoothly. If the bolt is not fully closed, the rifle might fire but
only a portion of the lug is against the receiver and that would put too much pressure on the lug.
Once you install the new bolt, checked head space, everything lubed, and after you load the first
round, make sure the bolt is fully closed and the slide all the way forward touching the piston. I
would do that for every shot for a while.

Maybe you just got unlucky and got a bad replacement bolt.

[Colter44]

i didn't replace the bolt the first time, the cmp did. I assumed they checked the head space.

[jak]

i didn't replace the bolt the first time, the cmp did. I assumed they checked the head space.

I wouldn't assume that cmp would check head space but since you sent the rifle back to them, they should have checked it.

The last service grade garand I mail ordered from cmp had a rusty trigger assembly, a bolt that didn't head space,
and a firing pin was so rusty inside the bolt that I needed a screwdriver to pry out the firing pin.

[Punch The Clown]

I wouldn't assume that cmp would check head space but since you sent the rifle back to them, they should have checked it.

The last service grade garand I mail ordered from cmp had a rusty trigger assembly, a bolt that didn't head space,
and a firing pin was so rusty inside the bolt that I needed a screwdriver to pry out the firing pin.

Now now Jak, we all know that the CMP test fires every rifle before shipping.

[jak]

Now now Jak, we all know that the CMP test fires every rifle before shipping.

Yep, you're right. We know that no shenanigans ever occur at cmp

[Old Guard]

Now now Jak, we all know that the CMP test fires every rifle before shipping.

Okay, Yes, If you really want to believe that...Firing them is Possible, but i beleive that some fall thru the black hole and are shipped, anyway..

[Old Guard]

Early production flat bolts were known to break at that area. I would suggest getting
a round bolt. The bugs were worked out by then.

certainly the first Time I have read about the carbine bolts breaking...I know, I have noticed a lot more round bolts in the rifles..

[Punch The Clown]

Okay, Yes, If you really want to believe that...Firing them is Possible, but i beleive that some fall thru the black hole and are shipped, anyway..

OG, next thing you're going to tell me is Santa Claus isn't real.

[Old Guard]

OG, next thing you're going to tell me is Santa Claus isn't real.

Punch, definitely not true, Santa still eats the cookies and drinks his beer, and the missus has a BIG smile on her face when she awakes???

[30calflash]

IIRC a lot of carbine threads elsewhere warned of using Wolf ammo. Mostly for the case mouth peening the chamber in the barrel.

Hope you get it sorted out. 30cf

[garandguy10]

Replace the bolt with a USGI round bolt, confirm head space, and then check bolt lug engagement using a sharpie marker.

[Frogman]

I have a Plainfield Carbine that did the same thing, can anyone tell me where to get that makers bolt or would a GI bolt work after head spacing.

[jak]

I have a Plainfield Carbine that did the same thing, can anyone tell me where to get that makers bolt or would a GI bolt work after head spacing.

A USGI bolt should work fine.

Lots of info here.
http://www.m1carbinesinc.com/carbine_plainfield.html

[musketjon]

Yep, you're right. We know that no shenanigans ever occur at cmp
Except for Punch's Reach Around.
Jon