Craft Gunmaking, No compromises, No corners cut, EVER

Monday, January 20, 2020

A New Ejector Segment for an A&A 453

This is a common enough failure with many side-by-side ejector guns, and the part usually breaks at one of two places, either at the end of the retaining screw slot, or the point where the half-shaft meets the face of the ejector.  In a design like this, with an integral guide half-pin positioned at twelve o'clock, failure of the guide pin is less common but it does occur.  The most highly stressed point of the part is where the retaining slot impacts the retaining screw.  This is because when the part stops against the screw, inertia carries the rest of the part onward, eventually failing it at the weakest point.
When ejecting spent shells, the weight of the empty hulls does a good job of mitigating this inertia.  Letting the ejectors trip on empty chambers is another matter.  It's always a good idea when opening an empty gun to place a thumb or index finger on the ejectors before they trip, in order to slow their speed, and prolong their life.  As described above, this isn't necessary when opening the gun after actually firing a shell (or shells).  It will never be a factor to even consider if you're not obsessively compelled to "relax" the mainsprings by dropping the hammers (a practice that has been debunked elsewhere on this blog).  Onward ho.....

The new ejector was blanked from a bar of O1.  From this point on, it is all handwork, except for the retaining slot, which is done on the mill.

The half-shaft is filed up completely by hand in the following manner.
Once I cut the blank from the parent stock, I filed 45 degree (approximately) bevels, then filed the "points" off the bevels.  Once it started looking half-round, I colored the entire surface with a black marker and then ran the appropriate radius gauge down the length of the half-shaft.  That left bright marks on the spots that needed to come down.  The process is repeated until the entire length matches the gauge.
The above filing stopped about .100" short of the root so that I could create the stress relief radius there.
The radius at the root was done by eye, using small,half-round files and polished using wet/dry paper wrapped around a short length of drill rod.

Next was fitting the face into its recess in the barrels.  Once it is fitted and the chamber ID is cut, the rim cut is made using (funny enough) a rim cutter.  Then the radius at the bottom is filed up and it's ready for the machining of the retaining slot and filing up the extraction cam and hammer striking faces.

Once all of the cutting, filing, fitting and polishing is done, all sharp edges are broken in order to ( in combination with the surface finish) deny cracks a place to start.

After heat treating and repolishing, it's assembled and ready to go back into service.

Thursday, January 9, 2020

Oh Yes, Even More WTF?

What can I say that hasn't been said too many times already?  Sometimes all you can do is scratch your head and laugh.

Unsurprisingly, the single trigger in this Parker Repro still didn't work, even after the work that this clearly talented gunsmiff lavished upon it. 

The double-single (not a typo) trigger in this FN SxS was apparently "fixed" by MacGyver, using a pocketknife and a paperclip.

A Dent Repair

This is a set of Parker barrels that had suffered damage in transit.  The right barrel was deeply dented on the underside, about ten inches from the muzzle.  It was quite a time-consuming repair, complicated by a lack of barrel wall thickness and having to refinish and blend the repaired area.  Due to the barrel wall thickness, I did not want to remove ANY significant amount of material from either the inside or outside of the barrel.  This meant that the barrel material had to be "moved" back into its pre-dent condition completely and very, very carefully to conserve what wall thickness was there.


Repaired and ready for refinishing of the repaired area

The repaired area is refinished and blended to the surrounding finish.  Yes it CAN be done.

Can We Just Stop With This Shit?

What shit is that you may wonder?  The wholly inappropriate use of welding to "repair" lockwork parts.  Regardless of how good an idea you may think it is, notwithstanding that "everybody" does it and, regardless of who says it's okay to do, WELDING ON HIGH-CARBON, OIL-HARDENING parts is NOT a good idea!
Just because these parts are steel does not mean that they are suitable for welding!  All steels are NOT necessarily weldable!  The higher a steel's carbon content, the less suitable it is for welding, at least the type of welding that is practiced by most "practitioners of the gunsmithing arts" (IE, hacks) in the business today.  Steels with a carbon content above about 40 points (that's 4/10ths of 1 percent) require special procedures for welding successfully.  Some of those special procedures include pre-heat, post-heat, VERY specific filler materials (some materials can only be successfully welded using the same alloy as the parent material), specific heating and cooling rates, etc.  Most of the lockwork parts in these old guns are made of oil-hardening, plain steels like 1075 or 1095 that contain anywhere between 6/10ths and a bit over a full percent of carbon.  This makes them, for all practical purposes, unweldable by the typical gunsmiff with a TIG welder that he barely knows how to turn on.  Oh sure, you CAN weld the parts and they might even look good.  Hell, they might even hold up for a hundred or maybe even two hundred cycles but, THEY WILL FAIL.  I can't tell you how many failed hammer notches, sear noses, bolts, tumblers and even springs I've seen that were "repaired" by welding.  They all fail in exactly the same way, with the weld portion cleanly separating from the parent metal, right along the weld seam.  Here's a good rule of thumb, if it's a through-hardened part, don't weld it.  Here's another, if it's a case-hardened part, ANNEAL the !@#$%ing thing before you weld it.  And NO, you can't anneal it in your kitchen oven.  The ONLY correct way to repair a part of this type is to replace it.  If no replacement is available, then you make one.  If you can't do that, don't call yourself a gunsmith because you're not.  Owning a TIG welder doesn't make you a weldor any more than having a Brownell's catalog makes you a gunsmith.  The very least you can do is attempt to know the materials with which you're working and act accordingly.  The client is paying for your knowledge, you should at least make an attempt at having some.  Welding is a career/science unto itself that, like any other complex endeavor, can take a lifetime to master.  If you think that welding up half a dozen or so parts a year makes you a weldor, you might want to rethink that.  Welding is also a very valuable component of gunmaking, when properly executed and where it is appropriate.
If, by some chance this is seen by any of the vandals that committed the acts shown below and you are offended: GOOD. 

A mainspring that had been welded, along with its replacement

Cracked weld "repair" of Fox sear nose

An Ithaca Knick sear nose with failed weld "repair"

Birdshit welded tumbler

Here's some truly vile work