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well thats pushing boundaries...
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Picture of Aaron Little
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This particular barrel has had hundreds of rounds put down range and has accounted for at least two Cape buffalo. The gun was bought second hand and put to use. The barrel was eventually pulled and set aside for future use, and ended up in my shop.
You see those three holes a few inches in front of the chamber? I presume they were for a secondary recoil lug. The middle hole leaves .047” wall thickness and is positioned about 2.5"-3" in front of the throat. The pressures of the .416 REM mag are in the high 50’s to low 60,000psi at the chamber, unsure of pressure at this point although being that close...That’s not a weak point I’d want right above where my hand goes.
I take from this:
- modern 4140 barrel steels are impressive.
-a good gunsmith is worth his price. That secondary recoil lug could have been attached differently.
-have guns you intend to buy that have been altered looked over by a good smith.
While evidence shows this barrel didn’t fail, knowing what I know about the barrel I would have personally never pulled the trigger on it. In the event of an over pressure situation this would almost certainly be a failure point.




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Posts: 1017 | Location: Mineola, TX | Registered: 15 October 2010Reply With Quote
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I saw a very similar situation on a Portuguese Vergueiro that came through my shop. The owner had a smith install a rear sight. Smith installed it about 3.5" from the receiver ring, just in front of the first step in the barrel. I forget exactly why the barreled action was sent to me but I had to pull the rear sight. The screw were pretty long so I measured the hole depth. Turns out there was less than .030" at the bottom of the holes. It was more than a few years ago so I don't recall the exact measurements but it was THIN, real THIN. Not a 4130 barrel, a Military barrel. Owner and I agreed it should be rebarreled.




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Posts: 4857 | Location: Lakewood, CO | Registered: 07 February 2002Reply With Quote
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Being a drilled hole the drilled point is the thinnest and the material becomes thicker moving toward the edge of the hole.
That probably creates a bridging effect over the thinnest section where the steel has yielded and now using the ultimate tensile strength.

Can you see any sign of the holes in the bore, such as a dimple?

It certainly is a testament to the strength of modern steel.
 
Posts: 526 | Registered: 13 March 2011Reply With Quote
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You are all panty-waists and namby- pambys. There is no strength issue here, at all. The surface area is too small to cause any problems; ever sectioned a Ruger #1 barrel with all the rib and anchor pin holes in it? Just measured a 30-06;
.031 wall thickness; They vary but many are in the .040 range. Do you think a major manufacturer would allow that if it was a problem, ever?
Do the math; you have 1100 pounds of pressure pushing against it on the Ruger #8 screws. On a #6 you have about 740 pounds; I used a 55K psi.
.047 wall thickness is enough. What if you drilled it all the way through? It still wouldn't rupture. You already said it had hundreds of rounds through it.
Chrome moly steel is very strong. I always shoot for a min .050 wall thickness.
Move on; no issue.
 
Posts: 17046 | Location: USA | Registered: 02 August 2009Reply With Quote
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Quickload will tell you the pressure in a barrel along the length if you do your part with the software. At one time I worked with a gent building 338's on AR's and helped with locating the pressure port hole.

Yea DPCD, Ruger drills them deep, I found this when I took the ribs off of No. 1 barrels.
 
Posts: 1445 | Location: Running With The Hounds | Registered: 28 April 2011Reply With Quote
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Wouldn't be the least concerned for reasons already noted. I would just liquid metal in some blanking screws, contour down to the barrel and forget about.
 
Posts: 3826 | Location: Nelson, New Zealand | Registered: 03 August 2009Reply With Quote
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I have a question. With a hole like this, if a good welder Tigged it up, would it be as strong as before and be a viable repair? Not trying to argue with anyone, I am just curious if this could be done.


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Posts: 2247 | Location: Houston, TX. | Registered: 18 May 2004Reply With Quote
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Yes it would but welding on the middle of barrels is not a good idea. Not that it will hurt, but it might warp it.
However, it doesn't need repairing.
 
Posts: 17046 | Location: USA | Registered: 02 August 2009Reply With Quote
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I recently had a client bring ove a rifle that was exhibiting some funny marks it the brass. One look and it told me one of the scope base holes had been drilled into the chamber. After a bit of discussion, he informed me that the rifle had been rechambered from a 7x57 to a 7mmRem Mag. Turns out the original d&t was Ok but the new chambering, being bigger, had cut into the hole. Funny thing though, the brass was not punctured, I think previous ones may have been but it seems like the brass filled the hole from inside out.


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Posts: 5499 | Location: Minnesota | Registered: 10 July 2002Reply With Quote
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quote:
Originally posted by Jim Kobe:
I recently had a client bring ove a rifle that was exhibiting some funny marks it the brass. One look and it told me one of the scope base holes had been drilled into the chamber. After a bit of discussion, he informed me that the rifle had been rechambered from a 7x57 to a 7mmRem Mag. Turns out the original d&t was Ok but the new chambering, being bigger, had cut into the hole. Funny thing though, the brass was not punctured, I think previous ones may have been but it seems like the brass filled the hole from inside out.


Did you fix it? I would have just put a little liquid metal epoxy into the screw hole and screwed the base back down, let the epoxy set, clean up the epoxy protruding inside the chamber, then forget the hole it was ever there or just refer to it as a pre-drilled chamber for crusher pressure testing Big Grin
 
Posts: 3826 | Location: Nelson, New Zealand | Registered: 03 August 2009Reply With Quote
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No, we replaced it. You want to buy the old one?


Jim Kobe
10841 Oxborough Ave So
Bloomington MN 55437
952.884.6031
Professional member American Cusom Gunmakers Guild

 
Posts: 5499 | Location: Minnesota | Registered: 10 July 2002Reply With Quote
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Picture of sambarman338
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quote:
Originally posted by dpcd:
You are all panty-waists and namby- pambys. There is no strength issue here, at all. The surface area is too small to cause any problems; ever sectioned a Ruger #1 barrel with all the rib and anchor pin holes in it? Just measured a 30-06;
.031 wall thickness; They vary but many are in the .040 range. Do you think a major manufacturer would allow that if it was a problem, ever?
Do the math; you have 1100 pounds of pressure pushing against it on the Ruger #8 screws. On a #6 you have about 740 pounds; I used a 55K psi.
.047 wall thickness is enough. What if you drilled it all the way through? It still wouldn't rupture. You already said it had hundreds of rounds through it.
Chrome moly steel is very strong. I always shoot for a min .050 wall thickness.
Move on; no issue.


Once more I think of Julian Hatcher turning down the Springfield barrel over the chamber; IIRC even with only a one-sixteenth-inch wall he had to use a proof load to blow the side out.
 
Posts: 4915 | Location: Melbourne, Australia | Registered: 31 March 2009Reply With Quote
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Picture of eagle27
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quote:
Originally posted by Jim Kobe:
No, we replaced it. You want to buy the old one?


Got nothing to fit it to but thanks for the offer Wink
 
Posts: 3826 | Location: Nelson, New Zealand | Registered: 03 August 2009Reply With Quote
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