Stop-drill a crack

[ECG_88]

So I got this Winchester 59 aluminum receiver from my dad. I am currently in the process of cleaning it up. I have never fired it, but some previous owner thought heavy loads would be a good idea. These aluminum m59s can only take light bird loads, nothing over 1oz.

I want to try to "fix" this hairline crack that has developed. It has not gone all the way through the receiver yet and seems to just be on the surface. Can anyone give some guidance on stop-drilling the crack? I know I have to drill a small hole on both ends of the crack but I don't know how big the hole should be. Also does the hole need to go all the way through the wall of the receiver? I am thinking it should...

pictures removed - The pictures are huge and obnoxious when placed in this thread. Just look at the link

http://imgur.com/a/2tXUc

[ECG_88]

Or maybe I dont need to do anything as the crack is not deep?

anyone have an opinion?

[ar15barrels]

That crack came from the INSIDE towards the outside.
I would make the gun a wall hanger.

[ECG_88]

That crack came from the INSIDE towards the outside.
I would make the gun a wall hanger.

Can you explain the implications of it coming from inside the metal? Forgive my ignorance, how does it make a difference? If it is drilled wouldnt it still stop the crack and relieve stress? I read that it is done often on airplanes (although I know it is not a permanent fix). Maybe with low power shells, the receiver could still handle it?

Making it a wall hanger could still be an option. My interest in saving it is more out of curiosity and experimentation of what is possible than actual desire to shoot it.

[jericho89]

While drilling will stop the crack from spreading with normal stress factors you still have a weak area in the receiver where the highest pressures are. The reason why a receiver is strong is because it is a cylinder shape, once you dent or put a cut in a cylinder you lose all structural strength. And on airplanes the reason why they drill the holes is to prevent the vibration of the aircraft from making the crack creep... But they also put repairs over the crack. So unless you are going to have the crack drilled, welded, and magnafluxed (to check for any weaknesses or air pockets) you are playing with a potential grenade.

[ar15barrels]

Can you explain the implications of it coming from inside the metal? Forgive my ignorance, how does it make a difference?

Not inside the METAL.
Inside the RECEIVER.
The crack started on the inside and is on it's way to breaking all the way through to the outside.
The receiver is already toast in my opinion.

[ECG_88]

Not inside the METAL.
Inside the RECEIVER.
The crack started on the inside and is on it's way to breaking all the way through to the outside.
The receiver is already toast in my opinion.

Let us clarify. I think we meant the same thing, the wall of the receiver. I looked on the inside of the receiver and there is no crack. So I assume you meant the crack started within the wall of the receiver and then moved to the outside surface. A couple of the pictures show the inside of the receiver and there is a sort of rail there that aligns with where the crack is. There is no crack along the rail yet, the crack only shows on the outside. You are telling me that it will continue to crack through to the inside surface of the receiver and eventually split that rail?

[ECG_88]

While drilling will stop the crack from spreading with normal stress factors you still have a weak area in the receiver where the highest pressures are. The reason why a receiver is strong is because it is a cylinder shape, once you dent or put a cut in a cylinder you lose all structural strength. And on airplanes the reason why they drill the holes is to prevent the vibration of the aircraft from making the crack creep... But they also put repairs over the crack. So unless you are going to have the crack drilled, welded, and magnafluxed (to check for any weaknesses or air pockets) you are playing with a potential grenade.

I do see that point that the drilling and crack does make the receiver weaker. I have another question though. Is the rear of the receiver the part that handles the most stress? I was under the assumption that the barrel and chamber contain all the pressure. Does the stress from that pressure get distributed through the rest of the receiver? I have never seen a picture of a catastrophic failure where the back of the receiver has blown. I usually only see the front of the receiver near the chamber or the barrel blown. But if my uneducated assumption is correct, that the stress travels and dispersed throught the rest of the receiver. Then is that why you think it may grenade?

[ECG_88]

I was googling "Shotgun receiver failure" to do some more research and I came across this post in some other forum. the topic was a discussion about steel vs aluminum receivers:


kirbythegunsmith
July 10, 2007, 06:56 AM
Frame materials had been iron or steel, and brass, and then aluminum came into vogue, and titanium and scandium, and lately polymers of multiple flavors.

Every material chosen had been expected to have qualities that could be useful with a proper design.

Aluminum frames in revolvers can be rated +p as a matter of course.

Lightweight materials in magnum guns can seem mis-balanced, and recoil levels are elevated. A steel slide on a polymer frame does feel top-heavy, and most of the mass reciprocates.

The aluminum frame Ithaca 37 does lock directly in the same position in the aluminum version as the steel version. The bolt locking surface has more surface area to hold the load in the high-strength aluminum frame of those 37's than a steel bolt lock has in an 1100 or Beretta AL-2/301/2/3 steel barrel extension.

Most of the guns discussed have stresses induced into the frame during firing, with the only exceptions being the rotary bolt designs, like the Winchester 1200/1300/1400/1500 styles, and Benelli Nova/SBE etc.
Rotary bolts with balanced lug position divide the stresses of firing between the lugs that are evenly spaced or opposite another.

Two frames with different materials but similar stresses induced could be the Remington 1100/870 and Mossberg 500. These designs lock the bolt into the barrel extension...
at the top...
above and completely out of the line of the travel of the bolt and cartridge.

When the pressure of firing pushes the case back against the bolt face, that takes the slack out of the parts involved up to the locking block.
But it's only locking at the top?
Some level of force is going to be directed downward into the frame via the bolt slide/action bars in the frame guide rails, since the locking lug (being one-sided with the force) has the effect of a pivot, albeit at a mechanical disadvantage.
If the bolt face had 5000 lb. thrust against it, maybe 1000-1500 lb. could be exerted downward into the frame (these are example numbers, not measurements) due to the locking lug pivot of force.
The Ithaca 37 has the same effect due to the upper locking recess for the tail of the bolt pivoting a portion of the force down into the bolt slide/frame rails interface.
The Model 12 Winchester does this without benefit of a bolt slide with broad surfaces to distribute the stresses. That is one reason the later versions of the Model 12 had the square faced bolt face, trying to resist the pounding from the pivotal action. Slack in the parts makes for a more abrupt impact and pounding action, and the deformities that are generated increase the slack. Now the parts get even more of a running start before they are abruptly stopped.

One final note:
the Remington/Mossberg type bolt uses a movable locking block, while the Ithaca 37/ Win. M-12 style rock the entire bolt to lock.
The locking block is an integral part in the chain of force transfer, and any slack in the fit can result in the pivotal force to transfer partially through the locking block having a minor rocking/tilting motion. This tilt is restrained by the barrel extension, the pivot pin (Moss. 500) and the bolt slide locking block seat section. Therefore, the pounding actions possible may also manifest themselves in those points of impact, but ultimately the final absorption point is the frame, itself, in these design situations.
kirbythegunsmith@hotmail.com

I think the underlined portion may be similar to the 59. Is that why a crack is forming where it is? The bolt being returned with so much force that the rail is struggling to hold the bolt. This causing the rail to want to pull away from the receiver and a crack forming on the other side?

[ar15barrels]

it will continue to crack through to the inside surface of the receiver and eventually split that rail?

Yes.

[JAE]

It's already cracked all the way through. Your just SEEING it on the outside because it's being BENT OUTWARD. Crack propagation starts at the crystalline level (depending upon how austenitic or martensitic the metal) and eventually shows to the naked eye AFTER is has sheared through.

The proper way to fix a crack in a critical area like this would be to drill stop on both sides of the crack a distance recommended away from the visible end, back gouge the parent material minimum half way one side then back weld and fill, repeat for other side, hold true as needed during the process, re heat treat the material as needed, recheck to print and correct as needed, and finally perform some type of non destructive testing (magnaflux or x-ray) of the finished product. Then you will have done a good job. I may have missed some things but that's the basics.

Randall is right. Put it on the wall as a talking piece. Best place for it.