doublegunshop.com - home Forums General Discussion Classic & Custom Single Barreled Sporting Rifles @ doublegunshop.com Has anyone ever seen this front sight

Attach are a couple pictures of a retractable front sight that are the incredible workmanship of Tom Burgess. He did make more then one of these but I have no idea how many. I am very interested in understanding some of the finer details of its construction and assembly. If there is anyone who has actually had the please of examining one or better yet owning one and would like to share what you know please contact me with a PM and we can discuss.

The design and metal working are impressive!

I have seen a German sporting rifle with a front sight using the same principle, although it provided two different elevations. This one is for protection, by the look of it.
It seems a useful idea.

It seems like you could easily screw up and put the sight in the down position and forget to return it to the up position and then throw your rifle to your shoulder to take a once in a lifetime shot and there is no front sight.

What I am trying to clear up as I said in the original post are design and assembly questions. There are two mysteries in Tom's design: 1. How did he assemble and a fix the sight blade to the, I will call it the operating button. 2. How did he add "detents" to hold the blade in the retracted and deployed positions. If you zoom in of the attached pictures you can see some features that may be a screw in the top of the button and then what almost looks like a ball detent under the button in the base. But what do they do and how are the questions. There is also a question as to how the "pivot pin" is retained. The pin is a fixed and does not rotate. I know this by examining the position of the dust particles in the pics in the retracted and deployed position

Just guessing:

I think the sight blade and operating button may be machined as one piece. The screw thru the operating button could be used as a sight adjustment for a different impacting load. The screw could have a concave end to ride on the ball in the base (if that is what it is?)
Is it possible the blade/button assembly is held in the open/closed positions by a flat spring that operates off a notch in the blade/button assembly?
This would negate the need for ball detents.
As far as assembly, I can only guess the main pivot pin is a press fit???

Thanks Ken. I think you may be right on the blade and button being one piece. Over the weekend I did design in Fusion 360 a sight and during that design process I did identify that the blade and button could be one part. However as designed, currently there wasn't enough room for the spring detent inside. I think your idea is the best so maybe I will assess the dimensions again and see in more room is possible.
However thank you again for your input. As soon as I get a workable solution I will post pics of the 3D models.

I worked for years in several drafting/engineering departments. I went from pin and ink, to AutoCad, to Inventor etc. I ended my career managing a drafting/design group. I had some people in my group that were masters at modeling. Consequently , I can really appreciate the power the new programs have.

Ken, I drew up a design that I believe will work and incorporates all the original Burgess attributes, your input on the reason for the set screw, and a wider blade which makes manufacturing easier with the tooling I have available. Currently the design would retain the pivot pin as a press fit or a taper pin which I would want to be a little more positive so I will continue to refine. The basic dimensions of the sight are in the design however they will be refined as the project moves forward. The detent spring would be formed thru testing iteration when final piece parts are available.
The intention of the rifle is a both a retracted front and rear single folded leaf rear sight with a mounted Red Dot type sight mounted over the rear sight. Here are a few screen snap shots of the CAD model of the front sight.

Here is the basic intent of the rifle. Action and barrel (barrel is cut short in model for convenience in CAD environment) Caliber is 375 and is intended as a "Stroll" or "Walk-about" or "Back-up" rifle, take you pick. The bolt handle will not be straight in final.

You are not wrong. I used to hunt with a Beach sight for a while. It was always in the wrong position when I needed it. Flipping it up or down is really not what you want to be doing when waiting for that mule deer to stop and look back for a second. This sight, like the Beach and maybe even more so, can easily get a bit of gun case lint or a fragment of a leaf or other junk under that stop that would affect the height of the sight, resulting in a high shot. A retractable blade is kind of cool, but it is both a solution in search of a problem and a disaster lurking waiting to happen.

That said, LRF's design is pretty interesting, especially if it could be made to pop up to 2 different (and selectable) heights on demand. But more complexity is probably more opportunity for Murphy to be injected into the game.

Fred and Brent you seem to be focusing on backup sighting systems never actually intended to be used. The Red Dot, same as a rifle with a telescope, is the principal sighting system. In fact at the on set of the concept of this project no provisions for fixed opens sights were even intended. Then I saw the Burgess sight and thought I like the presentation and looks of it, kind of cool. Many, many rifles today are built with no provisions for open sight at all, as you know. This thread was meant as a discussion of design and engineering, which I thank Ken for his input and his understanding of the purpose of the thread. Not peoples would have could have failures at hunting in the field. It is not my job to cover them.

In my case, no. Definitely not a back up system. When using a front sight, what else is there? And anything that is a back up never intended to be used, is not, by definition a back up.

I hunted for a few years with a Beach front sight and barrel or tang sight. I like lollipop tang sights on lever rifles, but they are not repeatably adjustable on the fly, so a front sight with two different altitudes made some sense. One long, one short range. Unfortunately, as I said, the Beach sight is simply not the solution for the reasons mentioned. I got rid of it (actually 2 of them).

Ok Brent not sure what lollipop sights have to do with this thread

Only to try to make the point that it was not a backup system that I was talking about or had used.

My point in my original post, is that there are ways the front sight could go south on you, unexpectedly. And, implicitly, perhaps you could creatively think of something to do about it.

For instance, Could you design a shroud that goes around the front end of the sight in such a way that material could not get in the way of the two surfaces that control the height of the sight?

You seem to have taken my comments very negatively.
They were not intended that way, but merely to point out that there can be issues with adjustable front sites, and I have experienced them. It ain't pie in the sky stuff.

There is nothing quite like having a big mule deer buck staring back at you while you are fumbling around wondering how your sight got in the wrong position. Fortunately, it wasn't a charging cape buffalo.

How about instead of a press fit for the pivot pin,,make it a slip fit.
In the center of it's length there be a slightly smaller dia slot the width of the blade.
The hole in the blade for the pivot pin to pass thru be an elongated hole with round ends that match the pin dia.

The assemble..place the blade into the slot and push down into the base till the elongated hole shows clear thru the base.
This will require that the blade be pushed slightly lower than flush with the top surface of the base.
Then push the pivot pin in.

Release the blade, which is spring loaded by way of the small flat spring that toggles it up & down positions over a high point on the lower edge of the blade,

The spring will push the blade upwards and the blade will rise up into that slot and will pivot on that radius.
The pivot pin can't come out as it is locked into the base by the blade

Push down on the blade front and rear to allow the elongated hole in the blade to clear the pin and push the pin out.

Just a thought for a Field expedient repairable/replaceable front blade.

Too much coffee maybe??

No, (on the coffee) sounds do able. Let me work on it in the model and see. But thanks for the idea.
Update
I originally wanted a design in which the pin did not turn. The reason is because, no reason, other than the Tom Burgess pin did not turn in the pictures I showed. I don't know if that was planned or just it worked out that way. But I can't see any reason which should or shouldn't pivot, pin in base or blade on pin. Kutter's idea is the good one and very manufacturable and can easily be assembled/disassembled without tools.
So I think that checks all the boxes and I very much appreciate the design input. Makes me feels like I am back before retirement managing large design projects. With creative input of all kind. Some very helpful and then.........

Kutter, I have modeled up your concept and it does work however it has one negative that I am not sure I like or not. Depending on size differences of the major diameter of the pin and the groove diameter in the pin and then the amount of distance allowed between the centers of the offset diameters in the blade when the sight id fully assembled and the blade has popped up into the groove there will be a gap at the top of the pin that would so to speak let light shine thru from the side. Now is this an issue, I really don't know. How big is it well lets say if the major dia of the pin is .160 and the groove is .150 which would give a .005" retention of the blade which I believe is enough. And the offset of the holes in the blade is say .007" so you have fit clear of and extra .002" then the gap when assembled at the top would be at its worse .007". Tapering to nothing 90 degree toward the front of the hole.
Here is a pic. This is a bit embellished to enhance the issued. Actual dimensions given above would have a little less gap. Now first question did I understand your concept correctly?

You have found a flaw in my idea!

You are correct in that the blade/button (one piece) would have to stand away from the pivot pin the small amt that the clearance allows for TD and re-assembly in order for the idea to work.
The area where the button portion rt angles outward from the blade and forms part of the pivot for the blade is where it would show a clearance gap

Looking at the orig pics of the sight on pg1,,the blade/button piece is a nice, tight fit to the pivot pin in that 12 to 3 oclock quadrant. Enough clearance for it to rotate but that's it.

My idea would have to allow for the extra clearance needed to depress the blade downward into the base assembly to remove the locked-in pivot pin and to re-assemble.

Being one-piece, the blade and the button must be depressed as one and that nice tight fit at 12 to 3 around the pin (looking from the RH side) would have to be
compromised.

Well it was an idea anyway!

Back to the press fit pin I guess..

If I was to design such I would employ the over-center principle to keep it in the up and down position, and use the screw to control elevation.

Kutter thanks I will continue to noodle and I hope you do also.

gunmaker, are you saying that you think Tom's design use an over center concept or an original design of your own? If you had Tom's design in mind can you explain your thoughts?

I have been thinking this:
There is one possibility of design I was thinking about before Kutter offered his concept suggestion and that is to drill a hole perpendicular to the pivot pin in the base parallel to the sight blade or basically along side it. Into this hole a spring and detent pin would be insert. Then a small dimple hole would be drilled in the appropriate location on the pivot pin such that when the pin is insert the detent pin would fall into the detent hole in the pin preventing it from coming out and also turning. Disassembly would be a tap on the pin with a punch compressing the detent pin and spring there by sliding out. I will draw it up. Do you think it will work?

In reference to the over center design:

Are you suggesting a lobe type design on the bottom of the blade/button assembly that rides on a formed V shaped flat spring? Once the lobe rotates past the centerline ( either side of the V shaped spring) the blade assembly effectively snaps into either open or closed position.

Thanks,
Ken

Yes, that is one way to accomplish it.

I believe Tom used the over center concept, yes. The large pin fits snug to the front sight base, and the sight insert rotates around said pin. The screw on the top of the blade is for elevation adjustment of the sight. The small ball detent(appears to be) is a bit of a mystery. Possibly it was put in place as a “cushion” for the front sight insert snapping up. Or maybe it’s just an imperfection in the surface from the elevation screw.

It’s also possible that the over center spring isnt under the sight blade, but rather a spring loaded detent drilled in front of the insert. Judging by the square slot, the sight was held upright in the mill to create such, which would have been a great time to drill for a detent. You’ll notice some bluing wear on the sight insert which may support my theory, as well as an angular change. The over-center is timed so that it doesn’t take much movement to activate its opening.

Cashapp or Venmo is easiest.

This is the concept I mentioned in my last input and is very doable. The hole is drilled in at 28 degrees and does not mark the edge of the pin hole. so completely hidden. Field disassembly accomplished with point of a cartridge.

So I was strolling down the isle at the Tulsa show over the weekend and noticed a couple custom rifles on a table so stopped for a closer look. Was surprised to see this front sight on one of them. Don't think I have ever seen one before, and I find one a week after someone posts about it on the forum. What are the odds. Anyway, here are a few pics. Not sure how much help they will be. I will say the front sight blade is very hard to raise or lower. Not sure if it is by design or due to dried oil in the slot, but it was a two thumb job to press the tab hard enough to elevate the sight. Lowering was easier due having better mechanical advantage on the blade. It was certainly not what I would call snappy.

John

Wow John thanks, that is strange. Looking at the pics I see some major differences and actually considerably harder to make then the one Tom Burgess made. (the added difficulty would be in the area of cutting the hinge shape for the blade to rotate on. Perfect work for a wire cutter or a shape end mill) It may use the over the center pin concept which would not surprise me as being harder to operate. However, being stiff has it's advantages over the issue Fred was concerned about. Wish you could have gotten a pic from the top but I certainly do appreciate the 2 you posted. By chance you didn't get the name or info of the rifles current owner?

I’ve really enjoyed this thread. I appreciate LRF starting it. I enjoy learning about the engineering that goes into some of the detailed parts like iron sights. On the sights both LRF and John posted I noticed, when elevated, the sight places the brass sighting surface at what appears to be an exact and optimum 45 degree angle, much like a sourdough sight. Very impressive!

One question:
Is the sight base and barrel band one assembly??

I guess I should have taken a picture of the right side. The right side of the hinge pin on the one at the show had a large diameter head, just like the right side of the one you originally posted. It also did not rotate with the blade but stayed stationary relative to the base. I wonder if the small end of the pin might not just be a press fit in the left side of the base. The owner was not there either time I stopped by, but his friend behind the table did say that the metal work on this rifle was by Burgess. The rifle looked to have been more recently stocked and reblued. I am sorry but I did not get the name of the owner.

John

John that adds more info thanks. Need to think about it.

John, When you say it was "very hard to raise", was that all the way from start to completely erect or was it hard to start and then at some point there was a more or less snap to the erect position? This may help understand what kind of detent or spring holds the blade in position.

I think Tom used a stepped pin and it was most likely a press fit of some kind. That design has 2 issues IMO, first as I mentioned above the machining of the base requires a special ground cutter or use of a wire EDM. The cutter is fine if you intend to make multiple copies, in my case it would be just one copy if at all. Second, disassemble of a press fit pin has its own set of issues and wear would soon cause fit issues. (but of course it may never need to be disassembled) I think my design has some improvements in this area. BTW, my design takes full advantage the Tom's hard ground breaking design work and I fully acknowledge I am using that prior work, however that in itself is the nature of engineering. After all, Mr. Boeing (if there is or was one, with his 747 did indirectly steal Orville and Wilbur's ground breaking engineering/design work. )

I didn't want to fool with it to much as the owner was not present. As mentioned it took both thumbs on the tab to get it to move, however once it started moving it went all the way up, but certainly not in a snappy motion. It got somewhat easier once it started moving, but certainly did not snap into a detent. Felt more like closely fitted parts that had some dried oil or grease in them. Lowering it was considerably easier due to the added mechanical advantage.

If the rifle is still there come next fall I'll get a closer look. It is amazing how many guns are on the same table show after show. Sometimes for years. But that's another topic.

John

Great information thanks. If the gun is still there I am curious what the rest of it was like. Do you think Tom did more of the metal work? It's ok if you don't reply (I ask too many questions) I know you are busy and I do appreciate your input so far.

Very interesting question and I think they are a sight and a base ring soldered together. Is that what you see Ken?
Looking very closely at John's picture there is a separation line right where the sight base sits on the ring. Full length of the sight base, both pictures.
Or I am crazy. (I know I am but that's a different story LOL )

It was on a military Mauser if I recall correctly. Custom scope bases. Caliber 270. Stock was a well done modern classic style. The guy behind the table who was not the owner did say that it had been restocked. Sorry, but that is about all I got.

John

Lynn,

It would be an even more impressive design if it were a one piece band and base assembly. I suspect it’s a soldered assembly as you’ve noted which is good enough for me!!😀

I look forward to updates, I loved all of your previous design threads.