Notifications
Clear all

Building a reproduction 1926 Lincoln Jeffries pistol  

  RSS

Garvin
(@garvin)
Curator in Chief Admin
Joined: 2 years ago
Posts: 4498
9th October 2018 17:05  

Building a reproduction 1926 Lincoln Jeffries pistol

With thanks to John G for this magnificent description of a monumental project. 

 

 

 

One of my quirky interests lies in patented spring air pistol designs that never went into production, and it has been great fun making working examples of these and seeing how they perform. At the same time this has taught me how to use a lathe, as well as some of the basics of gunsmithing. After my last project, the next one on my bucket list was a pistol design patented by Lincoln Jeffries Jr. in 1926. This describes a fixed barrel overlever pistol in which the piston moves rearwards, as in the Webley pistols. (British patent No. 254,640. 1926) 

I can only assume that LJ’s motivation behind this design was to overcome the criticism of the Webley pistols that their barrel cocking system could lead to bent barrels. At first sight the patent seems obvious, and just involves the addition of an overlever cocking arm to the basic Webley design. However, when you think about it, no overlever pistol had ever been described before and so it was an original concept. Furthermore it obviously did have commercial potential, as LJ’s overlever system was many years later copied and marketed successfully in the Weihrauch HW45 and the BSA Magnum 240. Possibly with aggressive marketing, Lincoln Jeffries Jr. could have made a dent in the dominance of the Webley air pistols with his design, but for whatever reasons he never brought it into production and any workshop prototypes will be long gone. I thought that a reproduction of this pistol would make a nice addition to my collection. 

Usually I post my projects when they are completed, but I thought this time I would put my neck on the line and map out the project as it progresses, problems and all. Hopefully it won’t stall and there will be a finishing line, but you can’t always tell with these things. There is always the possibility of meeting a machining challenge that you can’t overcome with amateur equipment and so the project could be permanently shelved. I do not work to a schedule and tend to dip into my projects as and when the mood takes me, so getting to the final product could be a long haul, or might only take a couple of months. I have already made a start, and this is a summary of the results so far. I will add further posts as things (hopefully) progress. 
The drawings were studied and a build strategy mapped out, and then the drawings were scaled and the various dimensions calculated. As always, the build starts with the carcase and everything else is constructed around that. The patent shows the carcase (cylinder, grip, muzzle and breech barrel housings) to be constructed as a single unit, presumably forged from steel and then milled and bored, but this was not feasible for me, and so the carcase was broken down into four more manageable parts as shown in the diagram. 

The components were the cylinder (1), the grip frame (2), the breech barrel housing (3), and the muzzle housing (4). The intention was then to make these individually and then braze them together as invisibly as possible to give a single unit. 
The cylinder (1) was made from a section of 1 inch OD precision seamless steel tubing, with a wall thickness of 2mm. This was first threaded at each end to receive the muzzle and breech plugs (the patent drawings show that the cylinder is designed to be accessed from both ends). The two plugs were turned down from round steel bar and threaded. The various steps are shown in the following sequence of pictures.

The grip frame (2) was made from steel plate as shown in the next series of images. It was first roughed out with a hacksaw [pics (a) and (b)]. As it was eventually going to be brazed to the cylinder it needed to have a half inch radius concave profile along the top edge so that it would fit as closely as possible against the cylinder wall and give the strongest possible bond. Luckily I was able to buy a reconditioned half- inch radius ball nose end mill off the internet at an affordable price, and this was used to mill the necessary curvature, which you can make out in (c).

The grip was then skeletonised, as shown in (e). The last picture (f) shows the finalised grip frame with holes drilled in it and threaded to receive the eventual grip plate screws. Here it has been placed against the cylinder before it has been brazed into position, and the two cylinder end plugs are also loosely in position. This is that stage of a build project that I particularly look forward to, as it is now starting to look like a gun and this gives you a lot more impetus to carry on and complete the project. 

I find brazing one of the most challenging aspects of gunsmithing, and when it comes to building guns I have found most of what is there in books and on the internet not particularly helpful for the amateur. Everyone seems to say that capillary brazing is the only way to go, but trying to do this at a temperature of 800oC while holding two relatively large components in precise alignment is all but impossible without very fancy equipment or a huge amount of practical experience. It is not the same as soldering, where the temperatures are only around 300 oC and you can use a soldering iron. Also when capillary brazing a large area joint you can’t be sure that the brazing metal has penetrated the whole area. I have done a lot of experimentation and have found out the hard way what can and can’t be done so I now use a kind of sweating technique of my own, which requires more preparation of the clamping system in advance, but does seem to give consistent results and good strong joints. As no two jobs are exactly the same a lot of thinking has to go into how the parts can be held together accurately while they are being held at a red heat. This Lincoln Jeffries pistol is going to involve me in five separate brazing steps, all with different problems to overcome.

Brazing the grip frame to the cylinder had special problems of its own, because of the awkward shape of the two halves for holding, and because the size of the two halves made heating the joint with a blowtorch to a red heat impractical due to heat conduction. So it was decided to heat the whole thing in a mini-furnace. To prevent lateral movement of the two parts during heating holes were drilled through the frame into the cylinder and two loosely fitting locating pins fitted as shown in this picture.

The pins were trimmed down. A layer of flux and a section of thin silver solder foil were sandwiched in the joint, and the gun was then held unclamped in a specially made frame as shown in the next picture. The whole assembly was then placed in the mini-furnace and heated to 800 oC until the brazing solder had completely melted and filled the joint. The weight of the cylinder bearing down on the grip forced out excess silver solder and ensured a very close contact between the two parts, so that the brassy yellow brazing layer was virtually undetectable after cleaning up the joint. The pins could then be filed down until they were invisible.

Making the barrel was in comparison very straightforward, and involved turning down an old rifle barrel to the right diameter and then threading the breech end.

The next stage was to make the muzzle and breech barrel housing blocks (3) and (4). A steel block of the correct width and height was drilled with a barrel pilot hole and was milled along one side with a ½ inch radius concavity so that it fitted snuggly against the cylinder. The block was then sliced into two pieces to give simultaneously the muzzle block and breech block with their barrel pilot holes in exact alignment.

The hole in the muzzle block was enlarged to give a sliding fit over the barrel, and the hole in the breech block was threaded to accept the threaded end of the barrel. 

The next picture shows the two blocks fitted to the barrel after they have received some additional shaping. Note that the breech block end face is angled so that it will mate precisely with the overlever breech closure when it is eventually made. 

Finally the two blocks had to be brazed to the cylinder in two separate operations. Locating pins were used much as for the brazing the grip frame to ensure precise positioning of the blocks, but in this case brazing was carried out in the vise using a MAPP gas blowtorch as the heat source. This was quite tricky, as perfect alignment of the two blocks was critical, but thanks to the locating pins the outcome was OK. Here you can see the locating pin on the muzzle block.

When the two blocks were brazed in place, a check was made to ensure that the barrel could be inserted smoothly through the muzzle block and screwed tightly into the breech block. This shows the final result:

So having got the basic carcase of the gun sorted out, the next stage will be to make the cocking overlever, with its pivot pin, long links and barrel slider. The lever itself promises to be particularly difficult as it will be made up from four components involving two more brazing steps, where precise alignment of the various components will again be critical. I will be reporting on the outcome of this next phase, good or bad, in my next post, and with any luck even more progress - so watch this space!

In part 1 of this build project (patent drawing shown below) I had got as far as making the pistol main frame and the barrel. Despite the fact that my wife insisted that lawn mowing, hedge cutting and tree pruning were more important than any airgun project I have managed to sneak in enough time since then to make reasonable progress. It also helps that there has been so much dross on the telly these days. 

So here is an update of where I am now:

After completing the frame the next logical step was to have a go at making the overlever cocking arm.

According to the patent drawings, this consists of two parallel flat bars astride the barrel that are held together by a pivot housing at the muzzle end and a barrel closure block at the breech end. The relative positioning of these is critical, as the overlever arm describes a large arc during the cocking stroke and the barrel closure block has to mate closely with the breech block in the closed position. The patent depicts the overlever arm as being made from a single piece of steel, which is feasible of course, but would be extremely tedious and wasteful for me to do in practice. So I decided to see if I could make it from four separate components – two strips of steel bar for the sides and two separately machined blocks for the pivot pin housing and the barrel closure block. These would all then be brazed together. The advantage of this approach is that the various machining operations that need to be done on the two blocks would be much easier to deal with when they are unattached to the side arms.

Before starting the cocking arm, the position of the arm’s pivot had to be established. First the muzzle end of the cylinder with its plug in place was drilled through for the pivot pin, and the plug was then milled to provide the slot for the pivot arm (pics 1 and 2 in the following sequence of pictures). Anyone who owns a Webley pistol will recognise the format of the fore-end pivot system in pic 1, which Lincoln Jeffries has quite openly copied.

I found it hard to visualise the pivot housing in three dimensions from the patent drawings as it is only drawn in profile. So when in doubt with something like this I find it useful to make a rough mock-up in wood so that I can iron out all the problems before committing the work to steel. By a process of trial and error, the final shape was deduced to be as shown in pic 3. Pic 4 shows how it accommodates the muzzle barrel housing and the barrel. This shape was then used to make a steel version, as shown in pics 5 and 6. The extra two holes shown in the side of the housing in pic 6 are for locating pins when it will be eventually brazed to the side arms. Pic 7 shows how the pivot housing rotates within the muzzle plug.

The next step was to braze the pivot housing to the side arms. In the next sequence of pictures you can see how this proceeded (pics 8-12). The locating pins helped to hold the housing in place during the brazing process and also provided extra strengthening to the joint. After brazing they were filed down and with a little peening and polishing became virtually invisible. 

Once the pivot block was fixed to the side arms, the pivot pin needed to be made. This was turned down from mild steel rod and threaded, the result being as shown in pic 14. The pivot hole in the cylinder was recessed so that the head of the pivot pin would be flush with the cylinder (pic. 15). With this pin in place the swing of the overlever could then be used to locate the precise position of the closure block for it to fit snugly against the breech block in the closed position. With the help of locating pins the breech closure block was then brazed to the side arms of the overlever, giving the result shown in pics 16 and 17. Pics 18 and 19 show the resultant overlever in the closed position and open position.

Having got the overlever arm made and fitting satisfactorily I next needed to make the breech closure bolt. 
The patent drawing for this is shown in the following diagram. To make it easier to explain how it works I have coloured the main component parts. The bolt itself is coloured in red and blue, and is a single unit. The closure block section of the overlever is shown in green, and is internally threaded to take the screw section of the bolt. The bolt section shown in red is recessed to hold a breech sealing washer, shown in yellow. The rear of this section has a thumb lever, shown in blue. When the lever is rotated clockwise the screw moves forward and the sealing washer is forced against the barrel breech to make an air tight seal. Because the block is part of the cocking lever (not shown for simplicity), the pressure from the screw also serves to hold the overlever arm firmly in place.

Making the closure bolt looked like a relatively simple job to do, but as is often the case the simplest looking tasks can sometimes be the most troublesome. Unfortunately the patent drawings only show the bolt in left side profile, and the actual shape in three dimensions had to be guessed. 
From the patent drawing I assumed that the thumb lever favoured the left side of the gun as shown in pic 20. However, once I had invested quite a bit of time in making it, when it was fitted it in place I could see that it was clearly wrong. The screw needs to be turned clockwise to seal the breech, but my lever was shaped for an anticlockwise rotation. After a rethink I concluded that the thumb lever did not need to favour the left or the right hand side of the gun but could just be in line with the barrel as in pic 21. Once I had realised this it made perfect sense. It would have saved me a lot of time if I had made a trial bolt out of wood first, before committing to steel.

Ah well. Live and learn!

I decided to start over again and make the closure bolt shown in pic 21 by the sequence shown in pics 22- 27 , bearing in mind that I wanted it to look as similar to the patent drawing as possible. 

A steel rod was turned down and threaded as in pic 22. A blind hole was drilled into the end of the threaded portion to receive the breech sealing washer, and then a slot was milled into the side of the rod to receive the thumb lever. Pic 23 shows a bar of steel which will make the thumb lever milled down to fit tightly into the slot. The bar was then roughly shaped to form the thumb lever (pics 24 and 25). It was then brazed into place and filed down to give the final result shown in pics 26 and 27.

Pic 28 shows the screw in place in the closure block.

It might be worth saying a bit about the brazing process here, as this project seems to be involving more brazing steps than any of my other projects so far. For brazing I like to use silver solder alloys, which melt at about 800 oC (a dull red heat) for steel as they give extremely strong joints. The main difficulty however is getting the required temperature while holding the two component together. I found that a very useful way of doing this was to make a pair of removable jaws for my vice which were drilled to take 6mm steel rod. This way short pieces of the rod in opposite sides of the vice jaws could could be used to hold two components tightly together, leaving a large gap between the jaws with easy access for the flame from the blow torch. As the area of contact between the rods and the components is small, heat conduction into the body of the vice is minimal, so it is easier to get the components up to the required temperature. The ends of the rods can also be custom shaped if necessary to grip awkwardly shaped components. The next picture sequence shows how the vice was used for brazing the thumb lever to the breech closure bolt. 

Pic 29 shows the opposing two rods that are fitted into the vice jaws, and one of them has a metal block at one end with a V-groove for holding curved objects. Pic 30 shows the embryo thumb lever clamped against the screw bolt ready for heating with the blow torch. The two mating surfaces have been coated with flux and a thin sliver of silver solder sandwiched between them. The area around the work has then been packed with high temperature resistant thermal insulating wool, (aluminium silicate) as shown in pic 31. This stuff is excellent as it is stable up to at least 1200 oC and helps keep the heat concentrated around the work and also protects the vice from getting too hot. Pic 32 shows the work after brazing at a red heat and cooling. As you can see, the insulating wool is completely unaffected by the heat and can be used over and over again. One advantage of this technique is that it gives you complete control of the joint pressure, as the vice jaws can be tightened with one hand as the heating proceeds, leaving one hand free for the blowtorch. 

Next on the to-do list was the cocking barrel slider unit, show in red below, which I feel Lincoln Jeffries over-engineered somewhat:

There is no real reason why the slider has an extension along the barrel, as the cocking action would have been just as smooth without it. Other overlever pistols work well without such a refinement, and it did make the unit a pain to make. However, wishing to keep as close to the original patent description as possible, there was nothing for it but to essentially hew it out of a single block of steel, wasting a lot of metal in the process . The construction sequence is shown in the following series of pictures:

(a) A steel block of the appropriate length was bored to be a sliding fit over the barrel;
(b) and (c) The sides of the block were milled down to leave square protrusions on each side to make the pivot pegs;
(d) and (e) The protrusions were turned down on the lathe to give them a round profile.
(f) More metal was milled away to provide the slider lug, and the barrel slider section was rounded off in the lathe. 
(g) The lug was shaped and recessed to fit in the cylinder slot 
(h) This shows the slider in place on the barrel. 

I reckon that in the whole process about 80% of the metal in the original block ended up as swarf!

To complete the cocking mechanism there remained the side links to make. These were constructed from steel strip, one end of each drilled to take the slider pivot pegs and the other end drilled and tapped to accept the pivot screws, as shown in picture 33 in the next picture sequence. (Incidentally, despite appearances these pictures were not taken in black and white but full colour. I find that sometimes when taking closeups of very shiny metal parts with flash it is better to use a white background. This can often create the impression of zero colour.)

The pivot screws, which serve to attach the side arms to the overlever arm, had to be made so that they were a loose fit through the overlever while at the same time they could be screwed tightly into the side arms. The length of the side arms and the distance between the two holes also had to be calculated carefully, so that the correct movement and positioning of the piston would be ensured before and after cocking.

Pic 34 shows the completed slider unit. The pivot pegs, which are a snug, freely rotating fit in the side arms, should according to the patent be peened over to keep the arms in place. However I found that when the slider unit was in place over the barrel, as in pic 35, the side arms were firmly held on the pegs without the need for peening. In fact it would take a large screwdriver and brute force to move them. So peening was dispensed with, which had the advantage that disassembly and reassembly of the gun was simpler. 

So I have reached the point where about 80% of the gun has been completed and I distinctly feel that the end is in sight. All that remains now is to make the piston, trigger, trigger guard and grip plates, and then to finish the gun with its lettering and bluing. I am looking forward to this last phase and to shooting the gun. The final product is not going to be exactly pretty, but then again Lincoln Jeffries was not noted for his artistic pistols. Functionality was always his prime objective as typified by his grease-gun Lincoln. For me the ugliness is part of the charm of these vintage designs. 
I will hopefully be posting these final stages of the project in the near future as Part 3 of the series, barring some major disaster, such as my lathe giving up the ghost or my workshop burning down !

In part 2 of this quest to make a reproduction of the 1926 Lincoln Jeffries overlever pistol I rounded off by saying that only the piston, trigger, trigger guard and grips remained to be made. Fortunately Lady Luck smiled on me and everything went relatively smoothly and I am happy to say the gun is now finished in its entirety. Here are some pictures.

For those of you interested in how I tackled the final stages of the project, here are some details of how things progressed.

The first sequence of pictures shows how the piston was made. I could have made it from a long section of solid steel rod by turning it down and boring out the interior, but it was much easier to make it from steel tubing. First the piston head was made by turning down a short section of solid steel rod, as in pics (1) and (2). It was made so that it would fit tightly into a section of thick walled steel tubing that would make up the body of the piston. The tubing was turned down to give it the correct profile and diameter as shown in pic (3). After cutting off surplus tubing the piston head was inserted into the tube and brazed in place. The piston head face was then drilled, tapped and countersunk to accept a 3BA screw, as shown in Pic (4). A two piece leather piston seal (Pic 5) was made using a former to shape the cup washer. The completed piston with its seal, which was a snug but smoothly moving fit in the cylinder, is shown in pic (6). 

The trigger system depicted in the patent is a simple one- piece unit. The trigger was roughed out from 5mm carbon steel plate with a hacksaw and filed to shape (pic 7) . It was drilled with a pivot hole and also a hole to receive a small spring (pic 8). The sear was carefully angled and polished to give as smooth a let-off as possible (not easy with this sort of one-piece trigger), and it was finally hardened by heat treatment. Pic (9) shows the trigger in place in the grip frame. 

The next item on the to-do list was the trigger guard. This, according to the patent drawings, had a relatively thick curved cross section and was attached to the underside of the cylinder and grip edge with two machine screws through shaped ends . This meant that it had to be cut out from 5mm thick steel sheet, rather than fabricated by simply bending steel strip. The procedure is summarised in the next picture sequence.

After marking out the rough shape on a piece of 5mm thick steel sheet, the concave part was removed by a combination of drilling, hacksawing and filing, as in pic (10). One edge of the metal had to be milled to a half inch concave profile, as shown in pic (11), so that it would fit tightly against the curved cylinder surface, and this was done with a ball-nosed end mill. The outer curve of the trigger guard was then cut (pic 12), and the final shaping was achieved after a lot of filing, giving the result shown in pic (13). Countersunk holes were drilled in each end of the trigger guard, and corresponding holes drilled and tapped in the cylinder and grip. Pic (14) shows the trigger guard screwed in place on the pistol. 

The final piece of the construction work was to make the grip plates. The patent drawings shows them to be made of wood, each fixed to the grip frame by two countersunk machine screws, and having a profile that tapered from the base to the top. Two suitable sheets were cut from a large block of walnut as shown in pics (15) and (16). These were then tapered as shown in pic (17), using an end mill fitted in my lathe. It is great that a metal-turning lathe can be used for accurate wood shaping like this, and it has solved all sorts of woodworking problems for me which would otherwise have been very difficult with ordinary woodworking tools. The same versatility can’t be said for using a wood turning lathe on metal ! 
The walnut sheets were then cut to the shape of the grip frame and drilled with countersunk holes to take the grip screws. The patent shows the screws to bed into grommets rather than make direct contact with wood, and so I made four brass grommets (pic 18) which were a press fit in the grip plates. Pic (20) shows the grip plates screwed in place on the grip frame. 

At this point the plates were flush against the edges of the frame, but in the patent they are depicted as being slightly smaller than the grip frame, so that a narrow border of the metal frame was exposed around the grips. The grips were then slightly reduced in size to create such an effect. After two coats of thinned down polyurethane varnish, with steel wool rubbing down between each coat, the result was as follows:

With all the machining work completed and everything fitting together OK, it was time to think about the cosmetic finishing touches. There was the metal finish to choose – vintage blue, modern blue, or nickel plating, but before that there was the all-important lettering to consider. I wanted to have the lettering in two locations on the gun - on the overlever there would be indicated the identity of the pistol, its patent number and the fact that it was a reproduction, and on the grip frame where it would be concealed by a grip plate there would be my personal details. The important thing was to ensure that the gun was permanently recorded to be a reproduction, so that at some future date it couldn’t be passed off as, or mistaken for, an original protoype.

The system I use for lettering I have described before and involves first producing a protective resist on the metal surface with the lettering 
areas removed accurately by a photo process, and then etching the metal away in the exposed areas by electrolysis. It is a tricky process and quite time consuming. It is also the most stressful, because if you get it wrong it could disfigure your hard-won project for ever. It is well worth the effort though, as I have come across many airguns with no lettering on them and it is so frustrating knowing that their history will probably always be a mystery.
Picture (21) shows the blue photoresist coating on the grip frame with a transparent sheet printed with the lettering placed on top. After exposure to uv light and washing off with sodium carbonate solution, the resist film in the lettering areas is removed to expose bare metal. Pic (22) shows the grip frame after electroetching away the metal in the unprotected areas and then removing the rest of the blue film. 
Pic (23) shows the lettering produced on the overlever. 

It was decided to give the gun a deep black hot-blue finish, rather than a more muted vintage blue finish, as this was less time consuming and in any case the project was not intended to produce a simulation of a 1926-made prototype, but to be a 2018 interpretation of a 1926 design. 

So how does it perform?

I decided to fit the pistol with a Webley Mark 1 pistol spring, which meant that I could directly compare the performance of my pistol with that of the all-conquering Webley pistol design of the same era. The dimensions of the two pistols are very similar, with the same cylinder diameter and near identical swept volume. The Lincoln Jeffries has a swept volume of 21.5 cc, slightly less than the Webley at 22.5 cc. I am sure this is no coincidence, and Lincoln Jeffries Jr would almost certainly have used a Webley pistol for his design calculations, knowing that the Webley was about as efficient as you could get for that size of pistol and cocking effort. He would not want to market something of inferior power.

With this spring in place and the piston lightly oiled, the gun cocked and fired perfectly. The cocking sequence is very similar to the Webley although loading the pellet and closing the breech is a little more fiddly as the tap lever has to be tightened up by about one or two turns to give a tight seal.

I was surprised that the trigger was not as fierce as expected, and it gave a relatively smooth let-off not requiring too much effort. Using Webley Grand Prix waisted pellets, average weight 7.3 grains, the pistol gave a reasonably consistent muzzle velocity averaging 350 fps over ten consecutive shots (highest 356 fps, lowest 340 fps). This equates to a muzzle energy of 2ft lbs or 2.7 joules. 

A good condition straight grip Webley Mark 1 was used for comparison. To my surprise this gave an identical muzzle velocity of 350 fps with the same pellets. However, this is not exactly a fair comparison, given that the pistol was probably 85 or more years older than mine. To put things in better context, a mint boxed Tempest was examined with the same pellets, and this gave an average muzzle velocity of 360 fps. So it seems that the Lincoln Jeffries design could match the power of the Webleys without too much trouble, but how did it compare in other respects? These are my observations after putting about a hundred pellets through the gun:

1. The cocking stroke is easier to start than that of the Mark 1, and requires slightly less effort to complete the stroke. However, it is (not surprisingly) noticeably harder to cock than the Webley Senior with its longer throw.
2. Although the cocking stroke is a bit easier than the Mark 1, after taking a few shots the cocking lever feels painful on the hand due to its ridged nature. In contrast the round barrel of the Mark 1 is much more comfortable for repeated cocking and firing.
3. The barrel opening and closing sequence for the Lincoln Jeffries is not too tedious, but suffers in comparison with the Webley. After loading the pellet in the breech it is much more satisfying to be able to close the barrel with a single click rather than to have to tighten up a rotating lever.
4. The fact that the front and rear sights on the LJ pistol are fixed is a big negative, but I suppose that this would have been changed if the gun had ever gone commercial.
5. Cosmetically the overlever is also a negative, and unless it could be proved that the Webley pistols frequently suffered from bent barrels, this feature would not have done the gun’s saleability any favours. 
6. The one-piece trigger is not as smooth as that of the Webleys, and requires a bit more pressure. 
7. The accuracy, in my limited 12 yard tests, seemed to be much on a par with the Webley. 

The likely manufacturing costs of Lincoln Jeffries Jr’s overlever pistol were not likely to be any less than those of the Webley Mark 1, and would probably have been greater because of the casting/ machining complexities of the overlever with its tap loading unit, the barrel slide, and the awkwardly shaped carcase. This, combined with the shortcomings mentioned above would help explain why Lincoln Jeffries probably never took his overlever pistol into commercial production. Or at least, if it did make into production it was an extremely short-lived venture. 

An original prototype

When I started this series of posts about two months ago ( http://www.airgunbbs.com/showthread....ncoln+jeffries ) I was talking about Lincoln Jeffries and his pistol when I said (quote) “he never brought it into production and any workshop prototypes will be long gone.” Now often truth is stranger than fiction, and this is a good example, for a few weeks later I had to eat my words. Just as I was putting the finishing touches to my gun, an actual example turned up. This was after more than 90 years of its lying somewhere in limbo! Maybe it was just an incredible coincidence, or my resurrecting this design disturbed something in the fabric of the universe. Spooky. This smacks uncannily of the Webley Whiting story, where the original also lay hidden for almost 80 years and when it was found after a diligent search it turned out that by coincidence Mac Evans had just completed making a copy based on the original patent drawings! 

Pictures of this prototype have been shown in another post on this forum ( http://www.airgunbbs.com/showthread....ncoln+jeffries ). It is not exactly the same as the patent pistol and it has a different grip and trigger arrangement, but the basic design principles are all there, and importantly it is marked “Lincoln Jeffries” and “Prov Pat” . You can see that it definitely is a prototype of this design from the following comparison.

Interestingly the grip and trigger is taken from the Lincoln Jeffries Scout push-barrel pistol of the time. The prototype is also marked with the number 7 which raises the question whether or not this gun is an early discarded prototype or one of a short production run of the finalised version of the pistol. 
I favour the early discarded prototype theory for four reasons: 
Firstly, if it was a production model why would Lincoln Jeffries Jr call it the Scout when he was already selling a push-barrel with the same name? 
Secondly, the pistol is marked Prov Pat, suggesting it could have been made before the final patent design was submitted.
Thirdly, the prototype seems to be rather crudely made, with for example the breech block roughly welded in place, the tap lever only roughly shaped, and a pin used for the cocking lever pivot rather than a machine screw. 
Finally, the positioning of the Scout grip and trigger places the sear at least 3 cm further to the rear than depicted in the patent, so reducing the swept volume to about half of what is depicted in the patent drawings. This would have meant a very low power level for the pistol, something more on the level of a Gat. That sort of power would have been commercially disastrous for a pistol of this likely build cost.

It seems more likely to me that this was a very early experimental stage of Lincoln Jeffries project, and he used the available Scout grip and trigger unit for convenience while he tested out the overlever system. Once he realised the low power level that this imposed on the pistol, he would have refined the grip and trigger arrangement to give the one shown in the patent.

I suspect that there may yet be found a prototype identical to the patent design, but as it could take another 90 years to surface I am not holding my breath!

 

 

 


Quote