Q: Rolling Block - Casting or forging flaw ?

OneBarfly

OneBarfly

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Hey Guys,

I received this Rolly lately. I really don't know what to make out of what looks like a crack on the left side of the receiver. It really doesn't go anywhere, but could originate from the pin area. What's weird is the heat treatment seem to flow around it. Is this nothing or something? Thoughts

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Might be superficial. Do you know anyone who can do dye or magnaflux testing? An aircraft mechanic I knew tested a part for me once. Wasn't a crack in a bolthead, but it looked like one on visual inspection.
 
I would take the action down and examine the interior of the action,especially around the pin hole area to see if there is any depth to it or if it is a surface scratch.Also if you were planning on using the action to build a rifle then you could always remove the original finish and see if it polishes out
 
Hello, Here's another picture. It's really too bad, I do like the bright case colour.

Also, I know that this uses a hollow-base bullet, but should you be able to drop one down the bore and have it come out the other side? Before you ask - yes, it's the right calibre bullet (original 12.7) Other than that, the rifle looks OK. Is this normal?

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I would think it maybe the case harding cracked but there looks like a 2 more cracks down from the top of the receiver towards the pin hole also. In my opinion this could be trouble. But see what some others think
John
 
It is a strange place for a stress related crack but could be a casting flaw. I would follow Tiriaq's advice and have it magnafluxed or Xray analysed. One of the local machine shops must surely have the facility.

cheers mooncoon
 
I'd go with a scratch t but we are looking at pics and you have it right there so trust your insticnts.

Magnetic particle Inspection is not going to tell you much, Unless of course a crack shows up in that pin hole. But I can assure you that if you can't see it with good light and good eyes even the most sensitive flourescent methods wont help you much. Also MPI is only going to tell you what is going on at the surface.

If you want to figure it out with MPI and don't mint refininshing the gun and know a good man with a draw file you could bring that whole flat down below the bottom of your flaw.

You might find what you want to know with a radiograph or x-ray but you better have a friend who is a Tech or a NDE shop that is interested in playing around with it cause it will get expensive fast. It will be a challanging shot to do flaw detection on that with a radiograph.

What you need is a real good Industrial Ultrasonics tech or a guy who can do flaw detection with Eddy current. Then they can tell you exactly what is going on in there.

What you are looking for is a Non Destructive Testing company in your area with a sympathetic ear. Don't wait till spring to get it done or they will be too busy. Now is the perfect time.

Look up ACUREN/Canspec/IRIS or a small NDT/NDE company in you yellow pages and then stop over at the shop at 7:45 and see if you can find someone to talk to. I 'd bet if your timing is right the project might just get some of the guys interested.

If you are worried about do not trust some guy with a worn out MPI yoke and dry powder to decide on the saftey of the piece!
 
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IMHO it's a surface imperfection or scratch. It was obviously there before the receiver was case hardened give the patterning. Since it was hardened and THEN passed swedish military muster, I would personally not even bat an eye about shooting it (with eye protection) - but your mileage may vary.

On another note I have one of these on the way as well, except in 8x58RD. not that it matters as it's been bought only for the action to make an unregistered .45-70 ;)
 
Looking at your second photo, it does look like a scratch. Can't see anything extending into the hole. Likely superficial. Just a thought, if it were a flaw, surely sometime during the last 125 years it would have opened up, if something was going to go wrong.
 
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