Is it possible to fracture a bolt face?

A

abbiboy

Guest
Need some advice.
I have a remington 700 action in 6.5x284. Gun was made by RW Hart. Today I noticed on the bolt face a line going through it. I'm not sure if it is a scratch from a piece of brass caught in it or if it's cracked. I have access to operating room equipment @ work so i took it in and looked at it under scope used in Arthroscopic surgery. It looks more like a scratch but i;m still concerned it could be cracked. I was shooting 50.5 gr. of h4350 out of the gun.

What do you guys think? Is it possible?

ty. Jerry
 
700 bolts are not that hard nor brittle... they are tough... I doubt it is fractured...
 
Have it checked by a qualified engineering firm.

They can magnaflux or ultra sound test it. Better to be safe than sory.

Nat Lambeth
 
Crack

While anything is possible, I would agree with Dennise and Al that a actual crack on the bolt face of a Remington Bolt would be extremely rare.

But then, a "piece if brass caught in it" would be just as remote as far as putting a notable scratch on a piece of 4140 steel at 34 RC Harness.

You can make some "poor mans die check" with some Marvel Mystery Oil and talcom powder. Warm the bolt with a hair dryer then put some Mystery Oil on the bolt face. Let it sit for about ten minutes, untill the bolt is room temperature. Then wipe it with a clean dry rag as clean as you can get it. Really clean. Sprinkle a little talcom powder on the bolt face. If it is a crack, youb will be able to see it quite well..........jackie
 
Me too

I have a Remington Factory 700PSS with the same look on the bolt face. My take is that Remington cast the bolts and the face "crack" is a casting flaw.

One thing I know - I have fired the gun MANY MANY rounds since I first noticed this "crack" and everything is OK and the :crack" has not changed in appearance.

But I sure may be wrong.
 
Travelor

Remington does not cast bolt noses, that being the part where the lugs are., They are manufactured from solid Chrome Moly Stock. That is then brazed to the back part, which is a piece of alloy tubing.

If this same mark is showing upon different bolts, I suspect it is a result of the machining procces, sort of like dragging the tool back accross a finished surface.........jackie
 
A crack on a Remmington bolt face would be very unusual. I'm not ruling it out entirely, as flaws in the metal are an extremly rare posibility (and I'm writing this from the land Murphy came from... his law is real!)

There are links to photos of a Yugo mini "mauser" with a cracked bolt face in the action failures thread at practical machinist forum, so some bolts can crack, but a yugo failure is not directly relevent to your 700.


Here's why, barring an extremly rare inclusion in the metal, I don't think it very likely it will be a crack:

Unless you have had a case head expand sufficeintly to pull the counterbore apart, the thinnest section of the bolt face is under compression during firing - that compression is not going to cause cracking, cracks need tension

you'd certainly know if you'd had a case expand that badly and the counterbore rim is more likely to expand (you'd likely have to hammer the bolt open if that happened) than the bolt face is to crack.

Normal failure mode for a strong, well sealed action like a 700 would be for the barrel to split and the receiver ring to split with a crack through each lug raceway. That takes one hell of an overload, or a "detonation".
 
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