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Double Rifles, Single Shots & Combinations >> Building Double Rifles & Gunsmithing

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transvaal
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Loc: South Carolina
Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Matabele]
      #298084 - 29/03/17 01:25 PM

Quote:

This is a fantastic build and a pleasure to watch unfold, thanks for sharing!

Can I ask how you determined the angle of conversion for the barrels?

And you asked to be reminded to share some info on the jointing process with the hinge pin removed and excess material left on the forward lump? I would appreciate hearing more on this if you could, thank you!




Mark;

The convergence angle of double rifle barrels is not an exact science by any means, and to me is largely a matter of experience. On this particular rifle I converged each barrel to the center line of the distance between the firing pin holes at about .040" at the muzzle of the 22.5 inches of barrel length--meaning that the center of the bores are .080" nearer each other at the muzzle than at the breech. This is a good topic for you to research with some of your current colleagues.

One of the members of this forum, Ron Vella, has built about 6 double rifle using Brno zp49 actions and I hope that he will provide input as to how he came about deciding on barrel convergence, as he is a expert at it.

I will remember to discuss the jointing of the barrels in future posts.

Thanks;

Edited by transvaal (30/03/17 11:51 AM)


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transvaal
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: transvaal]
      #298122 - 30/03/17 02:05 AM

On second thought to my comment above to discuss later the jointing of these shoe lump barrels with a wedge shaped rear lump forward surface (instead of a radius or as called in the trade "circle"), now is as good a time as ever.

I envy those gunmakers who have been trained and versed by a elder expert in the process of jointing barrels to the action of double rifles. What I am about to discuss is based upon what I have learned by the experience of trial and error. Trial and error learning, unfortunately is full of negative reinforcement and I think positive reinforcement is best in this subject. I am going to return to my saved photos in my computer database and post a couple here to use as references as I discuss what I learned in the jointing process of this DR.



In this photo you can clearly see that the forward surface is a wedge shape and that the shape is at an angle of some sort to the barrel flats. In this case that angle is the exact same angle (as determined by measurements with protractors) to fit face to face with the matching angle in the draw portion of the action's lump slot. You can also the clearly the forward lump's hook surface.

Beginning with the shoe lump platform alone I began to joint it to the DR's action in the same manner that as usual with jointing(at least to my mind), and that is with the action's hinge pin being the center rotation point of the arc of movement vertically of the shoe lump platform. I began to reduce by milling and filing the rear of the shoe lump platform to allow this platform to come nearer the action flat, with the goal of leaving .010"+ gap between the flat of the shoe lump platform and the action flats when the shoe lump platform is locked in place by the horizontal forward movement of the action's locking bolt (driven by the top lever spindle and its spring). The goal of the proper jointing in this case was that when the shoe lump platform is rotated in its vertical arc downward that when the horizontal action of the locking bolt occurs that the shoe lump platform rear surface is firmly set against the action face; and that the rear lump wedge is firmly set against the corresponding surface of the draw; and of course, the hinge pin has contact with the forward surface of the front lump hook(all of this is illustrated in the second diagram of page 15 of Vic Venters in a post above).

In order to be able to perform this complicated jointing procedure, I made a hinge pin that was undersized to what I reckoned I would finally need; and after I had reached a point to where the shoe lump platform was able to rotate downward to within a position that I reckoned I could work with to finalize the jointing(see photo below), I removed the hinge pin completely. I continued to fit the shoe lump platform to the breech face and action draw, without the hinge pin in place. When in this fitting, I reached a point nearer the degree of gap between the shoe lump flat and the action flat, I stopped and moved the shoe lump platform over to my vertical mill and milled the 1 inch radius grooves for the barrels to fit into. After this I brazed the barrels to the shoe lump platform and finished the jointing with the complete shoe lump barrel set. When I was near to my final clearance and hard fit up against the action standing breech face and the action draw, I made my final hinge pin to the diameter I desired and fitted all three points(standing breech face, draw, and hinge pin)by a scrape, file and so forth. Of course this took hours upon hours of work. But this is how I was able to have all three points to joint at the same time.

The results are that it is the rear lump and the hinge pin together that take the force of firing of the cartridge, not just the hinge pin.










Edited by transvaal (30/03/17 03:05 AM)


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Matabele
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: transvaal]
      #298130 - 30/03/17 07:58 AM

Many thanks for the explanation Steve, it makes complete sense the way you have done the jointing. I have rejointed quite a few shotguns and appreciate the time it takes to get it right. The shotguns we manufacture fortunately have a removable draw system, greatly simplifying the rejoint, however the older vintage guns are not so forgiving!

I look forward to the next installment.


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transvaal
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Matabele]
      #298135 - 30/03/17 09:40 AM

Mark;

Please comment in some detail if you can about how the replaceable draw works, such as is it dovetailed into the action and held by a screw; is it hardened? I have seen how the H&H replaceable draw is designed.


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Matabele
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: transvaal]
      #298253 - 01/04/17 07:08 PM

Hello Steve,

I will take some pictures of the draw system in the coming week, as they say a picture is worth a thousand words.

Hope everyones weekend is going well!


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transvaal
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Matabele]
      #298262 - 01/04/17 11:03 PM

Mark;

Thanks we all will be waiting to see your photographs, especially from an workshop of one of the innovators of modern technology to traditional made guns.

In the meantime, I will speak to the issue that is next in the building of the subject DR, and that is the making and installation of top and bottom ribs, as well as quarter rib for use with a scope and the front sight ramp. These items can easily be the source of too much weight added to the barrel, if one is not diligent.

In order to have minimum weight added to the barrels, I searched for a source of thin high quality steel shaped to the radius I needed for building ribs. I needed something in the range of a 1.5 inch diameter thin wall tube to cut a radius section. I was search for some such tubing with maybe .025" thickness. Where I found the source of strong thin wall tubing was with builders and suppliers of materials to the automobile racing business. They need very strong and lightweight tubing in the building of their automobiles, motorcycles and so forth. I found just what I needed on eBay from one of these firms.

I silver brazed a fore-end loop to the position I needed between the barrels as well as a cross piece between the barrels at about 11 inches from the muzzles, being careful to try to keep the barrels in the convergence angle as well as horizontal alignment.

The DR was test fired 2 times per barrel in an appropriate fixture with very high pressure loads.

I then built a temporary to mount a scope (as illustrated in this photo below) and tested the rifle impact point at 50 and 100 yards.



Although this photo is not of very good detail, you will be able to see that I milled a temporary ramp with dovetail slots to where a scope could be mounted and attached this ramp to temporary thread tapped holes to the top of the fore-end loop and another hole that I drilled and taped in the barrel support at the breech(this support was silver brazed in place at the time I brazed the barrels to the shoe lump platform).

The testing of the DR with such a temporary scope mount, or for that matter a open sight, is not necessary. However, I did it as I was going to stop in my rifle building process and develop a wildcat load for the DR and I knew that this effort would take several weeks or a month or so. Which it did. The load that I wanted to develop in the .38-55 McPherson cartridge case was a load that would equal the old .375 2 1/2 inch Holland & Holland flanged nitro express cartridge, but without the cost and expense of being able to purchase a couple of hundred .375 2 1/2" flanged empty brass cases, chamber reamer, loading dies and so forth--all of which would be more expensive than the route of using .38-55 McPherson.

I built the ribs, quarter ribs and so forth and attached them with tin/lead solder. I think all of you will be familiar with this task and know that it is time consuming. Purchase a copy of the video "A look Inside Holland & Holland" by www.gunmakersrow.co.uk. to view each step of how H&H builds guns and rifles, even the explanation and illustration of their DR barrel regulation and their barrel regulation wedge is there. The video may be difficult to find now, but it is out there even though it was made some 5-7 years ago. It is worth every penny it cost. I paid USA$50.00 for mine 5 years ago.

After the the rib installation it was time to regulate the barrels, which took some time to do. I use the Holland & Holland method of a vertical wedge between a machined front barrel bloc that fits the OD of the barrels at the muzzle as the photo below illustrates.

[URL=http://s1339.photobucket.com/user/lowveldt/media/SL59_zpsuuidrqte.jpg.html][/UR


After I have the DR shooting the way I want at 100 yards, I build a solid front barrel bloc for the correct distance between the barrels at the muzzle and solder it in place. The following 2 photographs are from the Holland & Holland video that I discussed earlier and they illustrate the vertical wedge and the final bloc as I have just discussed. After these two Holland & Holland photos is a photo of my DR's muzzle and the muzzle bloc.













Edited by transvaal (02/04/17 12:52 PM)


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transvaal
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: transvaal]
      #298368 - 04/04/17 12:24 AM

Of course, after regulation of the barrels of this DR, was the fitting of the original buttstock to my dimensions, reforming of the piston grip, checkering, leather covering a Pachmayr deaccl. recoil pad.

A few comments about the Brno zp49 double shotgun action to use as a DR action. I think that Ron Vella of Canada has demonstrated that these actions can be used with a number of lower pressure cartridges, and he has shown that on previous posts on this BBS that you can find.

These actions are coil spring side lock of the backlock design, and they use the typical Holland style cocking levers to engage directly with extensions of the lock tumblers to cock the tumblers. The cocking levers are very robust. Within the forward portion of the cocking levers is milled an area for the tripping levers for the activating the individual right and left side ejector kickers. The ejector system is of the Southgate design. The fore-end metal is robust as well and can be lightened by milling away and you can reduce its weight by 4 ounces.

However, one item that a DR needs, safety intercepting sears, are not a Brno zp49 component. I therefore set about to design and install a prototype safety intercepting sear for the action. The design I dreamed up is loosely based upon John Robertson's (Owner of Boss in early 20th century) Boss gun and rifle safety interrupting sear.

It is of interest to me and will be to you as well that I have not seen a safety intercepting sear that will allow the gun to be fired by pulling the trigger on the lock after the safety intercepting sear has been tripped. Let me explain with a hypothetical example: "You are on a Cape Buffalo hunt and a Cape Buffalo suddenly appears from nowhere and charges you at short distance. You fire the right barrel and hit the Buffalo, but he is still coming at you. You go to fire the left barrel and it will not fire no matter how hard you pull the trigger. For some reason the safety intercepting sear has tripped on the left side lock--maybe it was recoil from the right barrel firing that caused it. Nevertheless you are going to have to get away from the charging Buffalo quickly if you can."

It would be good to have safety intercepting sears that if they tripped and held the tumbler in position from accidental firing, that even though they held the tumbler in this position you could with extra pulling effort fire the DR.

That is the way the prototype safety intercepting sears work on my DR.

You will see from the photo that the lever that prevents the tumbler from moving forward and contacting the firing pin (strikers), is prevented from doing so by an extension mid way on the tumbler. I added this extension to the existing tumbler, by first removing and annealing the tumbler then drilling and tapping a size 8-32 screw thread hole and inserting a 3/32" diameter short section of O1 drill rod into the hole. Of course, the section of O1 drill rod had a smaller diameter portion that I had turned and threaded to 8-32 size. And upon further observation you will see that the larger diameter portion ("tumbler stud" is what we will name it) of the O1 rod extending from the tumbler is milled to an angle that mates to the angle of the top hook section of the intercepting sear lever.

For whatever reason that the safety intercepting sear of this design occurs the tumbler moves forward under its mainspring tension, but only moves .020"-.040" distance and is stopped and held by the hook to tumbler stud contact. However the angle of the tumbler stud forward surface and the angle of the intercepting sear lever hook is of such an angle that if one pulls hard upon the trigger (7-9 lbs of pull) the intercepting sear hook will move down from the tumbler stud and allow the tumbler to contact the striker and fire the DR. The intercepting sear lever is made of high strength alloy steel and hardened in order to withstand use as I just described.

the tumbler is rehardened and tempered. The tumbler stud is hardened and tempered as well, but is hardened and tempered individually-not while it is screwed into the tumbler.

The hardening and tempering of a lock tumbler must be done very carefully leaving the bent surface hard but not liable to chipping away during use, while leaving the cocking extension portion of the tumbler hard enough not wear away and the upper portion of the tumbler that contacts the striker hard but not so hard that it might begin to crack. If one has modern proper alloy steel to make a tumbler with, the entire tumbler can be heat treated the same throughout. Since I did not know the alloy of the steel of this Brno lock tumblers I heat treated them the way I just described.

Of course as you will notice I had to drill and tap a hole in the lock plate for the intercepting sear lever as well as make a pivot screw and a hair spring to hold the intercepting sear lever upwards.





Edited by transvaal (04/04/17 12:55 AM)


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Waidmannsheil
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: transvaal]
      #298386 - 04/04/17 06:28 AM

Very nice, clever design. Good idea as well, allowing you to continue shooting with a heavier trigger pull rather than having to re-cock the action while being stomped on by a buffalo. If you use carbide drills and taps you can avoid the annealing and re-heating. We use carbide all the time at work including countersinks as much of our work uses hardened material. I have been acquiring over time a full set of Ratio Drills which in my case have a drill length of 3D (Although it is actually slightly longer and you can get 5D and 7D etc.) and a shank of a nominal diameter which allows it to be held in a collet chuck. As the point is specially ground and the drill is very rigid, you do not need to center drill first, just plunge. They cost a bit of money but it is the best thing I ever did.

Waidmannsheil.

--------------------
There is nothing wrong with vegetarian food, so long as there is meat with it.


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transvaal
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Waidmannsheil]
      #298408 - 04/04/17 12:21 PM

You are spot on about the carbide drills and taps. Wish I had a set.

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Waidmannsheil
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: transvaal]
      #298430 - 04/04/17 07:58 PM

There is another way of tapping a thread into through hardened material without having to anneal first and that is with EDM. An orbital head is required, which unfortunately are very expensive so not all engineering shops that have an EDM machine will have an orbital head. Here is how it works, first you have to either drill a hole in the job using a carbide drill or you can spark a hole in using the EDM machine with a truncated electrode. Then you machine an electrode a bit smaller than the hole that you have just drilled in to the work piece. You then have to thread cut the electrode with the same pitch and tread depth as you would for a normal external thread. The electrode is then placed in the orbital head which is centered over the hole and lowered down to the thread depth required. The head is connected to the current source and turned on. A separate motor drive orbitaly oscillates the electrode and using a hand-wheel and inbuilt dial indicator, the extremity of the orbit is increased until the required thread depth is achieved. Below is a link to a YouTube clip showing how it works. There are several companies who make the heads and they all vary a bit. I was very lucky to be able to pick up a complete AGIE EDM machine and Orbital head for almost nothing before Christmas, but I had to build anew mezzanine floor to be able to fit it underneath. I should have the machine up and running in the next few months. If you machine up the electrode yourself than getting the sparking done by someone with a machine won't cost too much. Hope this helps.


https://www.youtube.com/watch?v=2n2h49jAhLg


Waidmannsheil.

--------------------
There is nothing wrong with vegetarian food, so long as there is meat with it.


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Matabele
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Waidmannsheil]
      #298590 - 07/04/17 07:11 AM

Steve, I finally managed to take some pictures to explain the detachable draw system. The system is not complicated by any means, and would be something readily achievable with manual machinery (although I would be tempted to modify it somewhat).

Here are some pictures of a draw out of the action to show the profile and slots which mate with corresponding races in the action body. Every craftsman develops their own method with things, but my approach with fitting these is to initally harden the draw and temper right back (steel is EN9) to allow easy filing. These draws are retained simply by a tight friction fit in the action body, and a degree of hardness helps to maintain a tight fit to the action as the part is tapped in and out during fitting. This is fine for shotguns but I would want to use some form of retaining pin if this were used on a double rifle.











The draw is the last thing to be fitted when actioning a gun, and it is preferable to have dialed in the desired amount of push and the barrels must be jointed down to the breech face. The following pic shows how the draw mates to the corresponding surface on the rear barrel lump.



I begin fitting the draw using good old lamp smoke, but once I get close to bringing the gun back on the face I will reharden the draw and temper back to a light straw. I will then switch to using a permanent marker, which is much thinnner than lamp soot and gives a clearer indication of the bearing. The high spots are taken down with diamond files until the gun is jointed back down. It must be noted that the draw is in effect attempting to hold the barrels off the face and care needs to be taken to ensure good engagment with the draw (you can feel the barrels "picking up" on the draw if you close the barrels slowly and feel for the slight drag) but it cannot be excessive or it will bring the gun off the face, even an imperceptible amount will lead to accelerated wear of the gun. The position of the top lever should be noted with the draw out of the gun, and the top lever should return to this same position with the draw fitted...if the top lever is held off then the draw is bearing too hard.

And that is it! A simple system, but care must be taken in its fitting. I hope this was of interest.

Edited by Matabele (07/04/17 07:23 AM)


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Waidmannsheil
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Matabele]
      #298591 - 07/04/17 07:42 AM

Very well done, a good candidate for the wire cuter where the radius of the insert can be made to perfectly match the radius on the lump if that was also wire cut. I also use a fine permanent marker which work very well. Great work.

Waidmannsheil.

--------------------
There is nothing wrong with vegetarian food, so long as there is meat with it.


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transvaal
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Waidmannsheil]
      #298596 - 07/04/17 08:18 AM

Mark;

Thanks so very much for the photos and the explanation of the replaceable draw. The method of retaining the draw in place is quite unique.

I like your comments on using a black felt marker. I find that much more useful than the smoke lamp alone. I believe that you are learning a great deal in this shop.

Kindest Regards;
Steve


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twobobbwana
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: transvaal]
      #298606 - 07/04/17 11:32 AM

Matabele,

I've used black felt pens for some time when fitting parts and have wondered whether the ink layered down on the part is thicker or thinner than "smoke". It's certainly more convenient.

Thank you for the photos and the explanation of the removable draw. Vic Venters book is certainly a great one for explaining a lot of this.

When you say that "It must be noted that the draw is in effect attempting to hold the barrels off the face and care needs to be taken to ensure good engagement with the draw (you can feel the barrels "picking up" on the draw if you close the barrels slowly and feel for the slight drag) but it cannot be excessive or it will bring the gun off the face"............I always assumed that the "face" was the breech face so therefore wouldn't the draw be moving the barrels towards the breech face ???

I think that, in Vic Venters book, with jointing a double rifle it said that the force had to be taken off the hinge pin or it may bulge actions at the hinge pin.......perhaps this is what the "draw" is doing when it fitted correctly in a double rifle. Venters does show the difference between the jointing of a shotgun and the jointing of a double rifle in the book.....the shotgun uses the hingepin as "bearing point" whereas the double rifle doesn't due to the greater pressures involved.

Not nit picking/arguing just testing my understanding of the principle.

Keep up with the great work and please keep us informed.


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Matabele
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: twobobbwana]
      #298760 - 08/04/17 09:26 PM

Quote:

When you say that "It must be noted that the draw is in effect attempting to hold the barrels off the face and care needs to be taken to ensure good engagement with the draw (you can feel the barrels "picking up" on the draw if you close the barrels slowly and feel for the slight drag) but it cannot be excessive or it will bring the gun off the face"............I always assumed that the "face" was the breech face so therefore wouldn't the draw be moving the barrels towards the breech face ???

I think that, in Vic Venters book, with jointing a double rifle it said that the force had to be taken off the hinge pin or it may bulge actions at the hinge pin.......perhaps this is what the "draw" is doing when it fitted correctly in a double rifle. Venters does show the difference between the jointing of a shotgun and the jointing of a double rifle in the book.....the shotgun uses the hingepin as "bearing point" whereas the double rifle doesn't due to the greater pressures involved.

Not nit picking/arguing just testing my understanding of the principle.

Keep up with the great work and please keep us informed.




Hi there! No worries at all, happy to discuss these sorts of things. You are absolutely correct in that the draw will attempt to throw the barrels towards the breech face, however you must remember that when fitting detachable draws the gun is already perfectly jointed and "on the face". So excessive bearing on the draw will throw the barrels towards the breech face as mentioned and therefore disrupt the joint and the gun is then "off the face", holding a gun up to the light that is bearing too hard on the draw shows a wedge shaped chink of light as the barrel rounds are now hitting the breech face first. That is what I was alluding to.

With regards to double rifles and detachable draws I personally feel that pulling the action out of the hook is excessive, and the amount it is pulled out of the hook has perhaps been exaggerated (for purposes of explanation of the principle) in Vic's description. I have Vics book and read that section a number of times nad it has always intrigued me. In my opinion when fitting draws it is more a matter of a distribution of pressures and not so much a physical movement of the action out of the hook. To my mind it makes no sense to not use the 10 odd mm's of hardened pin in conjunction with a well fitted draw, this would seem to be much less prone to wear over time. And if a draw is used with excessive bearing when it does wear the gun will very rapidly come off the face to quite a degree, as the pin is now not able to provide support. Also consider that pulling the action out of the hook as the barrels engage the draw will lead to a very pronounced two stage feel on opening and closing the gun.

Of course when no detachable draws are used then you have no choice but to joint the gun down equally between the hook, circle and breech face...as Steve has done with his gun. History has shown the old vintage guns holding up remarkably well using this same system, so I do not feel a detachable draw with too much bearing offers any advantages in terms of strength and longevity of the gun, but certianly aids in tightening a gun back up when a rejoint is needed.

It must be said I have never built a double rifle (although I plan to) and don't presume to put words in anyones mouth...It's just simply my thoughts on the matter.


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transvaal
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Matabele]
      #298765 - 08/04/17 11:15 PM

Mark;

I agree with you and it makes a great deal of sense to have both the draw and the hinge pin in equal support of the barrels during firing of the gun and or rifle.

As I was conceiving the idea of building shoe lump barrels and later during the actual building and jointing of the barrels to the Brno action, I jointed the barrels with the draw moving the front lump hook back from the hinge pin by .002". However, after giving consideration, I decided that it was foolish not to have equal distribution of forces during the ignition of the cartridge against the hinge pin and the draw.

Not all who replace hinge pins in double guns and rifles see the value of a hardened pin--such a preventing galling of the hook as it rotates against the hinge pin.

Edited by transvaal (09/04/17 11:39 PM)


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twobobbwana
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Re: Building, regulating & engraving a DR with shoe lump barrels [Re: transvaal]
      #298825 - 10/04/17 10:58 AM

Matabele,

"So excessive bearing on the draw will throw the barrels towards the breech face as mentioned and therefore disrupt the joint and the gun is then "off the face", holding a gun up to the light that is bearing too hard on the draw shows a wedge shaped chink of light as the barrel rounds are now hitting the breech face first. That is what I was alluding to."

Noted !!!!..............this would cause a gap ("off the face") until it is "blacked down" and the bearing/load is spread thereby putting the gun "back on face".........Makes sense to me.

"With regards to double rifles and detachable draws I personally feel that pulling the action out of the hook is excessive, and the amount it is pulled out of the hook has perhaps been exaggerated (for purposes of explanation of the principle) in Vic's description. I have Vic's book and read that section a number of times and it has always intrigued me. In my opinion when fitting draws it is more a matter of a distribution of pressures and not so much a physical movement of the action out of the hook. To my mind it makes no sense to not use the 10 odd mm's of hardened pin in conjunction with a well fitted draw, this would seem to be much less prone to wear over time. And if a draw is used with excessive bearing when it does wear the gun will very rapidly come off the face to quite a degree, as the pin is now not able to provide support. Also consider that pulling the action out of the hook as the barrels engage the draw will lead to a very pronounced two stage feel on opening and closing the gun."

Once again I agree that Vic has exaggerated this - relieving the forces on the hingepin - for illustration purposes. If the pin is not fitted to the hook then, upon firing, the hook would get a "run up" on the pin and cause battering...........and beat itself to death.

"History has shown the old vintage guns holding up remarkably well using this same system, so I do not feel a detachable draw with too much bearing offers any advantages in terms of strength and longevity of the gun, but certainly aids in tightening a gun back up when a rejoint is needed."

I have often wondered whether some guns don't hold up well due to lack of "spring" when jointed. Another concern is when fitting a new hingepin, thereby moving the barrels back to the breech face, is that they have to push the rear hook/lug out of bearing with the draw - thereby solving one issue and causing another. A removable draw would allow this condition to be addressed.

Transvaal,

".....I jointed the barrels with the draw moving the front lump hook back from the hinge pin by .002". However, after giving consideration, I decided that it was foolish not to have equal distribution of forces during the ignition of the cartridge against the hinge pin and the draw."

This makes the same sense to me. Refer my comments regard the hook getting a "run up" and battering the pin. I interpret Mr Venter's comments to mean that the fit of hook and pin was "eased" which may well mean just "taking smoke".

Vick Venters please chip in if you're watching this conversation.

Gents you do great work. Thank you for including us in this and answering my questions.


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4al2
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Reged: 27/09/11
Posts: 25
Loc: delaware usa
Re: Building, regulating & engraving a DR with shoe lump barrels [Re: twobobbwana]
      #298837 - 10/04/17 10:07 PM

I notice that is a 3 point disc remover tool,well was that custom made?And who made it?I been looking
for one.Can you get information on betting one?


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transvaal
.275 member


Reged: 19/01/13
Posts: 72
Loc: South Carolina
Re: Building, regulating & engraving a DR with shoe lump barrels [Re: 4al2]
      #298844 - 11/04/17 03:02 AM

Three point striker disc installation and removal tools are made by using a rotary milling device (rotary table and so forth) mounted under a vertical mill or an extremely accurate drill press. The rotary device allow precise 120 degree intervals to be selected in order to drill the holes. Without such a rotary device they are difficult to make and impossible for most hobby machinist. I make them and use drill bit shafts for the three pins that I have cut into lengths with a small diamond wheel cutter from the appropriate size drill bit (they are hard and will not break easily). I use thread locker to keep them in place. For example I used a number 50 drill for the tool for this rifle. I do not a present have a photo of the final striker discs that I made for this rifle but, I made the disc where the three holes were outside the outer diameter area of the cartridge primer, in order that if there were a primer expansion because of a over pressure loads, that the primer will not have any "holes" to flow back into as it becomes somewhat plastic in the ignition of the over pressure cartridges.

To make one for your rifle or gun you must first know the diameter of the three holes you need, and the exact distance from the center point of the striker hole to the exact center point of the three outer holes. Generally you want this measurement to be =/- .001".

Edited by transvaal (11/04/17 05:05 AM)


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transvaal
.275 member


Reged: 19/01/13
Posts: 72
Loc: South Carolina
Re: Building, regulating & engraving a DR with shoe lump barrels [Re: 4al2]
      #298886 - 12/04/17 01:11 AM

Quote:

I notice that is a 3 point disc remover tool,well was that custom made?And who made it?I been looking
for one.Can you get information on betting one?




Allen;

It occurred to me that if you need a 3 point striker disc tool, send my a private message and I will try to make one to fit your firearm "by long distance". If you are not able to either remove a striker disc and send it to me, or not able to measure precisely what you need in size, you can make an impression of the striker disc with very thin paper and a standard graphite pencil. That may enough for me to make you one.


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Demonwolf444
.224 member


Reged: 05/08/16
Posts: 3
Loc: Yorkshire UK
Re: Building, regulating & engraving a DR with shoe lump barrels [Re: Matabele]
      #298940 - 13/04/17 02:30 AM

Thank you for sharing your knowledge here; i have an old which was converted from muzzle loading using a shoe lump and the original barrels; these barrels are past use now and i hope to save the gun by making a new set which is something i have never done, i have a lathe and a mill and some new tubes; just entirely lacking knowledge or experience of the process so all this is very useful info. I realize its not a minor undertaking!

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