stupid question of the week: how are front sight fiberoptic rods secured?

[1KPerDay]

I've looked at my Hi-Viz one and it's got a cool internal spring that retains the rod (which is stepped for the flat spring) from moving rearward under recoil. Also the front hole in the sight is smaller in diameter than the rear (which prevents the rod moving forward under recoil)

Problem: I bought an Advantage Arms fiberoptic front sight for my 1911 Commander kit (which I love).

The old front sight is retained in its dovetail by a roll pin vertically through the front portion of the sight, down through the front of the slide.

I drove out the roll pin top to bottom (only way).

I drifted off the old sight.

New sight looks like this, without the fiberoptic tube installed.


The passage/hole for the fiberoptic rod is the same diameter front to back.
I drifted in the new fiberoptic sight, and lined up the roll pin hole with the hole in the slide.

I tried to install the new roll pin top to bottom. I can't get it started while also holding the punch and the hammer and the slide. I spend $50 on a set of roll pin holders from brownells. I wait a couple days.

I use the smallest roll pin holder to start the pin... worked like a charm.

HOWEVER.

I can't get the roll pin down far enough. It's now mushroomed at the top from my ham-fistedness. But it's flush with the top of the sight. Yes, I'm using roll-pin punches.

Which means:

the horizontal front-to-back hole through the sight is now blocked by the pin. So I just spend $30+shipping for a front sight that is no more functional than the plain black original one, and looks stupider.

I tried drilling through the pin from the front to allow the rod through, and to transmit light, but broke 3 drill bits (tiny ones).

Judging by the picture I must assume that the roll pin is meant to be driven all the way down PAST the channel for the fiberoptic rod.

So my questions are:

1. IF I were somehow able to drive the pin down further, what would retain the rod? Am I meant to trim the oversized rod at both ends and melt over the ends or something? There are no notches or enlarged ends or anything. Nothing I can see would retain the rod under recoil.

2. Anything sharp enough to cut through hardened roll-pins? :banghead:

 

[tightgroup tiger]

Wow, Carbide drill bits are the only bits that will cut through a roll pin. You don't want to buy those. I can't help but think that the roll pin you are using is to long.
Obviously, if you mushroomed out the end of it trying to drive it and this happened.
What I'm not sure about is when you say you drove out the original from top to bottom, does it have a through hole that the pin could be driven in from either end?

I'm not sure I understand what you actually have there or are trying to do because I can't see through the internet to look at your problem, but it sounds like you are trying to drive a pin that is to long into a blind hole, meaning the hole just stops and your roll pin is to long. That would account for the mushrooming of the pin.

I would get a dremel tool and grind the end off the pin to allow access for the optic pin to go into the hole as it is meant to and just glue the optics pin in with super glue. It will stay there.

Depending on what you want to do and what equipment you have to work with, you can buy carbide drill bit from McMaster Carr from a credit card and these bits will drill the pin but it still won't be easy to do and you will probably still break the carbide drill bit.

A dremel tool would be your best bet for getting inside that little hole without doing a lot of damage to the front sight. Most places that sell dremels also sell a large assortment of stone bits that would take care of this problem.

The local Lowes in my area has everything you would need to do this. It still will be a hard job and you will probably need more than one bit, but they are a lot cheaper than carbide bits that you will break anyways. Drill bits aren't meant to drill the side off of something.

I hope this helps, It would sure be easier to reply to this post it their was a picture of the sight on the gun showing the actual problem.

Hope this in some way helps.

 

[1KPerDay]

Thanks for the help.

I drove the old roll pin out from top to bottom (through the slide) which is the only way I could see to get it out. So it's not a blind hole. It goes through. The roll pin is not too long. It sure didn't want to go all the way in, however.

Any ideas on how the fiberoptic rod is meant to be secured?

 

[tightgroup tiger]

Can you furnish a picture of the front sight as it is now?

 

[tightgroup tiger]

Does you fibre optic sight pin you have not fit the hole size in the front sight?

 

[1KPerDay]

It fits fine... except for the vertical roll pin now in the way of the forward portion. I could glue it in the back portion but it doesn't transmit much light Maybe that's what I'll have to do.

It looks just like the pic up there, except the small vertical hole in the front portion is filled by a roll pin and the fiberoptic rod isn't inserted.

 

[tightgroup tiger]

You will need to get a dremmel tool and a stone bit that will fit in the hole and grind the top off the roll pin so the fibre optic pin fits as it should. They are normally a press fit of some type. If you mushroomed it like you said you won't be able to get the roll pin back out anyways.

 

[bbuddtec]

well offhand, I'd say the rollpin doesn't hold the optic, but I suppose it could, go past then insert tube, and drive upward from underneath?

 

[1KPerDay]

I thought about that, budd, but there's no real way to drive it from below unless you have a wicked offset punch or something. No, the roll pin definitely secures the front sight. You can see it from the side in the gap between the sight and the slide. I super-glued the fiber-optic in and snipped it off at the back. That'll work for me.

But this sight is NEVER going anywhere until it breaks off I guess.

 

[1SOW]

On a CZ with comp sights, the front FO rod is cut from 6" sticks of either 1mm or 1.5mm dia. FO rod depending on the sight option. Cut the rod about 1/4+" longer than the the sight hole. Hold the rod between thumb and forfinger and rotate it back and forth smoothly. I use a bic lighter to apply "minimum" heat necessary to "roll a ball" on the end of the rod. Vary the heat by moving the rod closer/farther from the "side" of the flame.
Once the ball is formed, let it cool for a few seconds and insert the rod with the ball end toward the shooter. Gently heat the front end of the rod until it expands enough to prevent backing out of the sight.

All this sounds complicated, but actually can be done quickly with very good looking results.. The ball can be formed just barely larger than the original rod diameter or up to 25% or so larger--your choice. I keep two or three pre-cut pieces with the ball end already formed in my gun bag.
Gun solvents play hell with FO rods.