Folding leaf detent design and lapping

[Scota4570]

Attached is a picture of a Baker sight.  The leaf is a little too loose. There is no play though.  I think I want to add a detent of some kind.  Any ideas on how to do a neat job?



I made the rifle from a parts set a couple of years ago.  I did nothing to the inside of the barrel.  The owner complained that it was cutting patches an making 2-foot groups at 50 yards.  I checked the bore.  IT was ugly.  There were bad tool marks on the lands from drilling and not reaming the bore. The rifling cutter was not properly sharpened and left ugly ridges in the bottoms.   There were extremely tight an loose spots when checked with a lead lap slug.  I hand to bash lap past the tight spots to swage it down.  The muzzle was flared.  After two day of lapping with 100 grit it is getting close to one size front to back.  The owner is a youtuber.  He took some pictures and videos of the lapping process.  Hopefully I can share those later. 

Question....Lapping compound?  I am using Clover #100.  IT cuts at a glacial pace.  I am on day three and still have tool marks in the barrel.    What so real barrel makers use? 

[whetrock]

I may be asking a dumb question, but would it be possible to just move the two outside hinge knuckles in a bit with a hammer and punch (punch with a hollow tip, so as not to damage the pin, if necessary)? I'm not talking about swaging the pin. I'm just talking about moving the knuckles toward each other so that they grip the center knuckle slightly. I don't know if they would move and stay, or just spring in and then spring back out again. But thought I'd ask.
It can be hard to hold small stuff like that, but it's often possible to glue the piece to a block of wood which can then be used as a handle for holding and positioning the workpiece. I've used hot glue for that. It doesn't hold that securely, but works okay for some applications, and you can get it to release simply by pouring rubbing alcohol on it. A friend of mine uses 5 minute epoxy to similar effect, and then heats the piece to get it to release.

I look forward to seeing more about the lapping process. I'm eager to learn more about that.

[Scota4570]

As I made it from castings there was a bit of drag.  It moves freely now.  I did some research.  It looks like adding a spring on the bottom of the dovetail that pushes up is the traditional answer.  That spring bears on flats or bumps on the knuckle.  I think a little piece of thin music wire will be enough.  IF not I can do something with flat spring stock, maybe a binder clip.   

[Daryl]

Perhaps you have it figured out, but that base looks a wee bit too short for a spring, to me.

[Scota4570]

I am thinking a V-Shaped piece of 0.015" music wired staked into a groove in the bottom of the base.  That would double the length of the spring and then some. 

It strikes me as odd that The original Baker had no means to keep the leaf from flopping.  When the rifle is on your shoulder with the sling the 300 yard leaf flips up.  IT is there when you bring it up to fire. 

If I can not make it work I'll make him a complete new folding leaf sight that accommodates a spring detente.   

[flatsguide]

Any room for drilling it and fitting a small coil spring and detent ball?
Richard

[kutter]

Mill or otherwise cut a slot about 1/8" wide the length of base on the bottom.
Deep enough to accept a simple flat spring  down into it .
In the center portion of that slot cut thru to the top so the center is open where the pivot of the blade sight is located.

Cut a simple flat spring to fit into the slot full length.
Stake it into place at both ends of the slot on the bottom of the base.
It should be able to be flexed in the center a bit so it needs some depth/clearance betw it and what will be the bottom of the bbl dovetail when installed in place.
Clock spring type matr'l works fine . Usually something can be cannibalized  from old mechanisms and parts if you are the never throw anything away type.

Take the folding blade from the sight and add a small dot of Hard Solder to the bottom of the center of the pivot tube. (Weld if you can do it w/o burning thru the tiny tube)
File that little added metal glob to make an 'over-center' point for the sight blade that pushes against the flat spring when the sight is pivoted up and down.
It will put tension on the blade to hold it in both the UP and in the DOWN positions if shaped correctly given the concept of over-center.

[Daryl]

That, or some variation of it would work.

[bluenoser]

Love a good challenge
I believe I would file a flat perhaps 1/8" wide on the bottom center of the blade and another flat at 90 degrees to it, or a little less, on the back flat.  Then install a flat spring similar to how kutter described so that the flat at the end put upward pressure on the blade.  Should positively snap into the upright and down positions.