Carbine Bolt Cracks ?

[leecork]

Today, I had a chance to examine four M1 carbine bolts, both round ones and flat ones, I found that 3 out of the 4 bolts had small hairline cracks present. These cracks ran from the front of the bolt (bolt face area) towards the back of the bolts, and the cracks varied in length from about 1/2 inch to 1 inch. They started at the bolt rim and ran towards the round hole that anchors the extractor in place (top to bottom).

I never noticed these before, and I have been shooting carbines with these bolts. Is this a normal cracking situation ? How unsafe does it make the rifle to shoot ? Thanks

[Tuna]

Cracks in a carbine bolts are not a good thing. The area around the extractor was the weak point in the bolt design. The type 1 was beefed up to the type 2 because of this but the problem was still present which led to the type 3 which improved the bolt but there were still some failures. Replacement of the bolts would be the correct thing to do now instead of continuing to use the cracked bolts as they will let go sometime in the future.