Thursday, September 22, 2016

From the Raw

This project is completely made from raw material, no rough forgings, no parts "pirated" from elsewhere and no CNC, EDM or castings.  Every part, screw, pin and spring was, and will, be made here, by hand with the assistance of manual machinery.  It's going to be a rising bite, bar-in-wood, self opening, leverless, single trigger double rifle with inboard mounted sidelocks.  The caliber is 7.62x51R (that's .30-30 Winchester on this side of  the pond).  The false outer lockplates will have hinged, spring-loaded "access panels" (or maybe crystal windows) so that the lockwork can be seen.

The blank frame and the block of 1020 from which I cut it.
 
The barrel lump was machined from a piece of 4140 hexagonal bar.

The vertical bolt that works in unison with the underbolt, and makes it a rising bite action.

The frame after further machining.  The right-side fence is rough chiseled to shape.

The top strap TIG welded in place.

The barrels contoured and fitted to the lump, and the top strap joint is refined.  Also shown is the underbolt, vertical bolt, link and pivot as they are assembled in the frame.  It's clear how the axial travel of the underbolt translates to the rising bolt's vertical travel via the link.

The right-side inboard mounted sidelock. The outside "lockplate" is simply a cover and obviously will be pinless. I'm going to incorporate a spring-loaded trapdoor in the outer lockplates to access the inner workings.
The cocking lever is also the mainspring. As the barrels open, the lever/spring rotates the tumbler to full cock where the sear will hold it. As the barrels are closed, the cam at the front will cramp the spring.
This also makes it a self-opener.
The lockplate, the bridle and the screws are 1020 (they will be case-hardened), the tumbler, sear, sear spring, mainspring and cocking cam are made of O1 (an oil hardening steel).

To give some idea of the amount of work involved, here is a photo of the lock bridle after machining the posts but before shaping it by hand.

I decided that the bridles should be pierced, in the interest of saving weight (not really).

After some more thought, I decided that since the locks will be readily accessible (and therefore visible), that they should be more visually appealing.  To that end, I redesigned the sear spring (it's now a single-leaf with a bridge supporting it), beveled the edges of the bridle and bridge and cut an ornamental pattern into the lockplates (which had to be remade).

With the locks sorted, it's time to make the triggerplate.  Here's a shot of it early on.

Here is the triggerplate almost finished.  Now I have to decide on a single trigger or double triggers.
I had originally planned on a single trigger but double triggers on a side-by-side do have a certain aesthetic appeal.  I also decided against the sidelever, which I had considered, in favor of direct operation of the bolt via a slide in the forward portion of the triggerguard.  This is similar in concept to what is used in the Ljutic Mono trap gun.  It also allows the action to be completely symmetrical and ambidextrous.

Now it's time to work on the pattern stock.

I made a new, more functionally and aesthetically pleasing bolt slide and fabricated and welded the tang to the triggerguard.

 Next was to make the left and right firing pin bushings, firing pins, springs and vent screws.

 The blank for the forend iron with a portion of the bar of 1020 from which it was machined.

With the barrel breeches brazed, the barrels blacked down and the bolts fit, and the assembly proof-fired, I rewarded myself with some fun work.  That work is chiseling the fences.






Tuesday, September 13, 2016

Correcting Excess Headspace in a Winchester 1890

Nope, it's not a shotgun and yes, I like .22s (good ones).  This Winchester 1890 had been restored (including a new barrel) and is cosmetically brilliant.  Apparently though, the breechface of the bolt had some pitting that was removed by milling the surface, thus creating an excess headspace condition.  The cases were rupturing when fired.  I would have welded the boltface and then remachined it.  Since I got the job after the fact, and refinishing the bolt wasn't an option, I took a different route.  I machined the boltface to accept a screwed-in insert.
The photos will explain.

The excess headspace condition, it's actually greater than shown here because I couldn't hold the bolt all the way to the rear (against the locking lugs) and also take the photo.

The breechface as it was,

 After machining for the new insert,

The blank insert installed,

 After machining and filing, the amount of excess clearance is evident by the amount that the insert stands above the boltface.

The finished job,



Saturday, September 10, 2016

New Ejector Tumblers for a Purdey Best

The owner of this Beesley action Purdey complained of weak ejection.  The springs were not the issue but rather, it was the geometry of the ejector tumblers.  The portion of the tumbler that the nose of the spring bears against before the tumbler trip point, was shaped in such a way that as the tumbler rotated toward the trip point, the spring was allowed to expand, rather than being held compressed fully up until the trip point is reached.  I fabricated, fit and heat-treated new tumblers and a new tumbler pivot and set the ejector timing.

Making the new tumblers, they are made from 1095 and heat treated for maximum wear resistance.

The new left and right tumblers, The blue lines indicate the difference in the shape of the spring bearing surface.  The new tumblers keep the springs cramped up until the over-center (trip) point is reached, thus imparting the spring's full stored energy into the tumbler at the point of release.

I also made a new tumbler pivot, since the original was distorted.  I also enlarged the threaded portion to the same diameter as the shank for added strength, and drilled and tapped the forend iron to match.

The parts ready for final assembly,

The forend iron assembly ready to be put back into the wood, the gun now ejects the empties cleanly over the shooter's shoulder.



A Watson Bros. Beesley Action SLE

Here is a Watson Bros. round body SLE, built on the classic Beesley action by one of the London trade's master gunmakers, Michael Louca.   This particular gun suffered a failed ejector spring cramping lever.
This part cramps the ejector mainsprings when the action is closed, so that the ejector segments, by pushing upon the ejector tumblers and standing breech, do not have to do that job.  This makes the gun easier to close, which is of no small consequence when one considers that the act of closing a Beesley cramps both mainsprings AND both ejector mainsprings simultaneously.  It also prevents the ejector segments from wearing against the face of the standing breech.

The failed lever,

The blank, machined from O1, the original was made from EN9 which is a British specification and equivalent to AISI 1055.  The added chromium and vanadium in O1 can only increase the lifespan of this highly stressed part.  From this point onward, it's all hand work.
 

The lever, filed up for thickness, with the spring bearing pads rough shaped and the pivot hole piloted,

 Checking the fit,

Making sure that the fit of the forward projection is correct in the frame slot.  You'll notice that the barrel stop plate has been removed to gain access to the slot.  The stop plate also serves as the fulcrum for the cocking lever.  You might notice that the barrel lifters are lying flat.  This is because the lockplates and pushrods are removed.

Here is the finished lever, heat-treated and polished.  The spring is integral to the lever.  You might think that being an internal part, it doesn't need to be finished to such a level.  You would be incorrect.
The essence of a best-quality gun is that they should look, and be, as good on the inside as the outside.

The lever during installation,

Here was another small issue, not from a practical standpoint but rather an aesthetic one.  The lockplate screw slots have moved past the horizontal when properly tightened.  This has zero impact upon the gun's function but just plain makes me nuts.  The gun's owner agreed, so I made new screws for each lockplate.

The screws were machined from 1020 and will be case-hardened and polished when finished.  The thread is 3BA (that's British Association).

Here is something that a good many "gunsmiths" in the country of my birth simply fail to comprehend, a properly fitted screwdriver.

After the slots are correctly indexed, the heads are engraved and then the screws can be hardened and polished.  I use a push graver and a 20x microscope.

The finished screws,

Here's a shot of the assembled gun.  The engraving is Watson Bros' "house style" which wonderfully complements the sleek lines of the round body action.  Louca's guns are all the more impressive for being completely made by hand.  Watson Bros. is one of a literal handful (if not the only) of London firms still making guns the "old-fashioned" way, with no aid of CNC, EDM or castings (ugh!).