Salvaging muzzle device from pin and weld?

[ar15barrels]

You could theoretically drill out the spot weld over the pin and the pin would fall out/be able to be taken out, then you unscrew the muzzle device.

How do you extract a hardened dowel pin that is pressed into place before it's welded?
Many of the pins I install get tapped into place with a punch and hammer.
They will not simply fall out once the weld is drilled out.

[ar15barrels]

Here is what happens when you simply unscrew it:



Often, you don't even get the muzzle device off because the barrel galls to the muzzle device.
I get some pretty crazy stuff sent to me after people thought they could do things themselves that they read on the internet are "easy".

[ar15barrels]

TIG would be my suggestion. You don't really need a lot of filler metal.

I don't add any filler metal besides the pin.
I prep the hole with a chamfer and leave the pin proud.
Then I fuse the pin down into the chamfer to fill in the weld flush to the muzzle device.
The extra pin length is effectively my filler.

[ar15barrels]

I’ve had mixed results removing pinned muzzle devices. First try was on a PSA upper. I ground off the weld, the pin fell right out and I was able to unscrew the muzzle device. Second try was on a friend’s upper of unknown origin. Seems like in addition to welding, the pin was press fit into the hole. I didn’t have the right tools with me to get it out, so my friend told me to do whatever was necessary, which basically resulted in destroying the muzzle device.

So my advice would be to use a slightly loose fitting pin if you are doing a new pin and weld. It will make eventual removal that much easier.

I fit the pin tight on purpose.
When you weld the pin to the muzzle device, a loose pin will pull up into the weld.
A steel pin is often only 0.025" down into the threads, it could pull up enough that the muzzle device would come off without trashing the barrel.
That type of job would fail the federal criterial of permanence.

By having the pin fit tight, the pin does not draw up into the weld.

When I do aluminum perm attach jobs, I put a steel pin in the bottom of the hole and then an aluminum pin on top.
I deform the aluminum pin so it has to be pressed into the muzzle device.
This keeps the pin in place during welding.
If an aluminum pin is NOT pressed in before welding, it will completely ball up on the surface when welding and there will not be any pin mush more than about 1/16" below the surface of the muzzle device.

[AregularGuy]

How do you extract a hardened dowel pin that is pressed into place before it's welded?
Many of the pins I install get tapped into place with a punch and hammer.
They will not simply fall out once the weld is drilled out.

Aaand.. .So much for my theory.