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Stuck pin in shotgun receiver

evesdropper

Plastic
Joined
Nov 26, 2009
Location
Omaha, USA
Hoping for some ideas. I have a shotgun with a 3/32" diameter pin in a blind hole I need to remove.

The pin started out as a screw tha was threaded at one end and a pin at the other. Previous owner broke the screw head off. I was unable to drill it out as it is hardened. Harder than hss anyway.

I have plunge milled the head and threaded screw shaft with a 1/8" carbide end mill. Now I am down to just the pin part. It is about 1/4" long. My only 1/16" end mill won't reach any deeper and broke tonight anyway.

I am left with a .09375" pin .250" long in a blind hole. I have .125" diameter hole all the way down to the remaining pin. There is a start of a .0625" hole in the pin. It is not very deep and wandered off center slighty when the end mill broke.

Any ideas?
 
It's a blind hole, not thru.

Sounds like you need to buy a carbide drill. If the screw and pin were once one piece I would have gotten them out in one piece not drilling into the thing at all, but what's done is done.
 
So it's basically finger-tight, if there are no burrs or obstructions to the fit? Meant to come out when you back off the screw portion.

The fully-committed method would be to make a pin that fits the end mill starter hole, and superglue/JBweld the pin in the hole. The least little bit of travel of either adhesive would seriously ruin your day, however.

You could try 'stir-welding' the new small pin onto the stuck older one. Worthy of lots of trial and experimentation prior to execution, to be sure. But it would be easy to do 'down in a hole' once you get the process down, and the local heating and cooling cycle could serve to loosen things up a bit. Or, lock things in permanently, for all I know.

The 'turn into chips' method of milling it away is probably best, but you'll need to clamp things down enough to avoid another endmill break. And, arrange so you can see well down in the hole.

Chip
 
Sounds like you need to buy a carbide drill. If the screw and pin were once one piece I would have gotten them out in one piece not drilling into the thing at all, but what's done is done.

I tried to get it out in one piece but the damage was done. I have a 3/32 carbide drill bit. I will have to make a more rigid setup to avoid breaking that as well.

photos attached. Its a tough one to photograph. Note that I did not make all the drill marks and screw up the lip of the hole. That was a gift from the previous owner.

image2.JPG
image3.JPG
 
So it's basically finger-tight, if there are no burrs or obstructions to the fit? Meant to come out when you back off the screw portion.

It should be a loose fit now that I have milled away the screw portion, however, it is refusing to budge. The problem started when the previous owner used the incorrect length screw and then severely over tightened it. The pin may be bent and preventing extraction also for all I know.
 
My idea - and it might not work.
I make mistakes/errors, probably more than most.

Make a tiny plug/support/drill jig/bushing to align the next bit.
Dam via modeling clay/similar.
Flood with water, use solid-rod coated diamond drill.
Depending, either drill through or enough to shrink fit a suitable drill rod into the piece for removal.
 
It may well be wedged in and the only way to get it out is drill it but if it's just stuck in by gunk there may be another way. An old trick is to reverse the point in a Dremel type (vibrating) engraver so the flat can be used to vibrate stuck parts. You would use a good penetrant and work on the end of the pin with the engraver. If successful you may be able to then turn the receiver so the pin is down and tap the receiver with a non marring mallet in an effort to make the pin drop down.

I'm curious - is that by chance a pin that holds a shell stop? It somewhat resembles the old High Standard pump that was notorious for problems with the shell stop and pin.
 
It's a blind hole, not thru.

That's what I thought, too. The idea was to drill a new hole that aligns with the old one, thus creating a through hole, so you could reach the pin from the other side and drive it out with a punch. If the new hole caused a problem after driving out the broken screw/pin, it could be plugged and welded.
 
Hat section drill bushing, make one to fit, and a carbide drill.

The drill may suffer some breakages along the way, clean up the tip with a dremel and a diamond disk if you don't have any better way to resharpen the bit.

I have done this sort of work for a living, done everything from drills, old carbide end mills, and dental burrs as the situation merits.
We never threw away any carbide end mills unless the were pretty much completely down to round shank. Anything longer got used for butchery type jobs, usually cutting seized and sheared off bolts out of helicoils on very expensive aircraft parts.

If you can reach with a dental burr, use one of those straight high speed air pencil grinders, The burrs will last much longer at higher speeds, and allow the burr to cut, rather than trying to force it in to the work. That just blows the end off the burr.

Cheers
Trev
 
Spark erode it out?

Not such a bad idea, really.

If you happen to live where there is a guy nearby that is not uptight about working on gun parts, a really easy option.

I have seen a pretty crude burner made up of plastic pipe, using a 12v battery and a battery charger, that would be a pretty decent outfit for this kind of work too.

It was wired so the current flowed through a coil wrapped around the plastic pipe, like a solenoid, when the electrode made contact, the electrode was retracted and the cycle continued. I guess this is basic 'tap burner' technology, but I had not seen such in person before.

Sure would solve the problem of the part being stuck in too hard to get out, but not solidly enough to drill or otherwise machine.

Cheers
Trev
 
How about centering up (indicating) on the hole and go in with a left hand spiral drill. As someone earlier stated perhaps it is bent and wedged. The LH drill just might un-wedge it...
 








 
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