An 'Artillery' Nambu and Lahti

[sheepherder]

In the first half of this thread, I pictured some of the steps in making my 'Artillery Nambu'. It turned out so well that I thought I'd see if I couldn't come up with a couple more 'fantasy artillery' handguns...preferably from the first half of the 20th century.

My second attempt is based on the Swedish M40 'Lahti'. Again I chose the Luger artillery rear sight paired with a modified M40 Lahti front sight. The Lahti uses the same pitch and diameter barrel thread as the Luger, but with a longer breech stub. This barrel is chambered in 9mm Parabellum.

(Please note - Not every step/operation is pictured. Oily hands, need to operate machinery, and not being able to mill/turn and shoot pics at same time preclude all operations being pictured).

Here is the first step in making of the 'artillery Lahti' barrel...



(1) I start with the 9mm barrel blank, about 9" - 10" long, 1 3/8" dia. This blank is from Green Mountain.

(2) Here I've turned both ends concentric to the bore and turned the breech stub down to .705" OD x ~.906" long. Entire blank was skim cut to make OD concentric with bore. 3-jaw lathe chuck, live center in tailstock.

(3) Threading the stub to 20tpi and turning the end for clearance in the Lahti receiver.

(4) Receiver is a nice snug fit on the thread. Receiver is a surplus Husqvarna M40 receiver I obtained from Numrich or Sarco some 20+ years ago. No serial, never used, as far as I could tell.

At this point it was necessary to mill the barrel top level with the receiver so that it could be removed for machining without losing the timing. I greased the threads, loosened & torqued it down 6 or 7 times, then milled a flat level with the receiver top. To do the torquing, I had to make up a special receiver wrench. The next series of pics shows -



(5) Thinning the excess metal where the taper will be.

(6) Rough cutting the 9mm Parabellum chamber - Finished, showing 9mm case in chamber. Brass piece shown in some pics is just a thread protector, internally threaded and trued to bore. Reamer is from Clymer, solid pilot finishing chambering reamer. High-sulphur content cutting oil from Ridgid, running lathe at lowest speed, feeding in 1/32" at a time; pulling out, blowing chips away, and re-oiling each time. I use a Clymer floating reamer holder in my lathe tailstock to feed reamer in.

(7) The special receiver wrench, made of 1" aluminum. Also shown are two special inserts for my lathe tool holder.

(8) Rough milling the rear sight base and barrel shoulder, using a rotary indexing head with attached 3-jaw chuck and tailstock.


The next set of pics shows more roughing out the sight bases -



(9) Ball milling the rear sight base; making it similar to the Luger rear sight base, using a 3/8" 4-flute ball end mill. In the past, I've cut partly-round sight bases in 4º increments; this time, I used 2º increments. Looks much nicer!

(10) Milling the barrel shoulder, still using the 3/8" 4-flute ball end mill.

(11) Milling out the dovetail section; 5/8" 4-flute end mill.

(12) Milling the dovetail for the Luger rear sight, 60º 4-flute dovetail cutter.

Next set of pics -



(13) Luger artillery sight fitted.

(14) Rough milling the front sight base & band.

(15) Turning down the rear sight base [front incline].

(16) Turning the taper. Following the lathe work, I doubled the spindle speed and progressively wet-sanded the tapered section with 220/320/400 grit wet or dry sandpaper. Not really polished, but smooths out the join where the two taper cuts meet.

The next step is milling the front sight base and barrel band.



(17) Milling the front sight band, using a 1/2" radius corner end mill, 2º at a time, 180º clockwise, 180º counter-clockwise.

(18) Finishing the band milling.

(19) Cutting the 1/8" slot that will become the front sight blade dovetail. I've decided I prefer the barrel band and front sight base as shown at http://www.gotavapen.se/gota/m40/pist40_4.htm and below -



I like the square band/blade as opposed to the stepped ramp.

(20) Cutting the 40º dovetail, using a Harvey 2-flute cutter.

That pretty much finishes the front sight blade dovetail. Next, I need to trim back the muzzle and face & crown it.



(21) Turning down the muzzle to same dia as end of taper.

(22) Excess barrel has been cut off and the muzzle faced & crowned. I'm using an internally tapered split barrel vise insert to hold the barrel in the lathe chuck.

(23) Barrel is 98% finished, minus a front sight blade.

(24) Installing the barrel in the receiver. Spirit levels used to index parts; squib rod in bore to eliminate any crushing from barrel vise; aluminum receiver wrench used to protect receiver finish.

Next will be fabrication of a front sight blade.



(25) Finished barrel and Luger rear sight mounted on my M40 Lahti, minus a front sight.

(26) Rought milling the new front sight blade, out of a piece of bar stock.

(27) Cutting the 40º dovetail, using a harvey 2-flute 3/16" dovetail cutter.

(28) Top of pic is the finished dovetail pressed into the barrel; bottom is the excess bar stock hacksawed off.

Next is milling the new front sight blade square.



(29) Blade has been milled square with base. I went with a simple 'Luger 1900' style base and band.

(30) Three shots of the blade being thinned.

(31) Milling the slope to the finished blade.

(32) The finished 'artillery' Lahti barrel mounted on my Husqvarna M40.

Some oblique views



(33) Just showing finished 'artillery' Lahti from different angles.

There are a couple of milling operations yet to be completed to the barrel; accelerator cut, extractor cut, and feed ramp cut. I need to remove the barrel for these operations, but since the main milling/turning is completed, and anything else will be hidden, I thought it was time for a photo shoot!

...And that concludes this exciting chapter of "Days Of My Lives"...

[sheepherder]

Originally Posted by Edward Tinker

very cool - I like the Lahti better than the Nambu (which is not what I thought I would think)

In that case, here's a bigger pic...

[sheepherder]

Getting ready to finish up these two 'artillery' barrel conversions.

First will be the Lahti. Still needs a feed ramp, extractor notch, and accelerator cut. And dust cover installed.



(34) Cutting feed ramp with barrel installed. Need to match the partial ramp angle in the barrel extension.

(35) Barrel removed; milling extractor notch. Doing it a bit differently than usual.

(36) Milling accelerator notch. I did two long Lahti barrels some 25+ years ago; can't recall how I did it.

(37) Dust cover installed between barrel & extension, barrel torqued into extension for final time. Tools in pic are -

-- Barrel vise
-- Barrel reinforcing rod
-- Receiver [barrel extension] wrench
-- Receiver reinforcing block
-- Spirit levels
-- Wrenches/sockets

The refinished barrels/receivers are on the way back and pics will follow...In the meantime...

When my Lahti M-40 bolt was disassembled for refinishing it was found that the firing pin spring [14] was broken into two pieces.

It still functioned (I shot it dozens of times) but it is still something that I think should be removed & examined.

The firing pin and spring are both held in place by a pin [13] which needs to be driven out to clean & inspect the firing pin/spring.

Pic attached.

[sheepherder]

I got the barrel assemblies back yesterday and this morning I tried to take some pics. Hazy overcast, but too windy. Couldn't stand anything up for pics, so I moved inside. Crappy pics but if I can get good outdoor weather I'll replace these later.

I tried to find some light colored background material in ~ 2' x 3' sizing; Wal-Mart had nothing, Office Max only had gray foamboard. I bought a 2-pack of that, but it is not a good background. The guns fall over occasionally while shooting the images, and leave a white dent.

The refinishing turned out pretty good. Not quite how I'd wanted it, but beggars can't be choosers.

I left the original receiver 'sights' [notches really] on both pistols, as the uppers are swappable with the OEM ~4" barrel/receiver assemblies. The Nambu as mentioned on pg 1 is in 7.65 Parabellum caliber as that cartridge has approximately the same characteristics of the 8mm Nambu. The Lahti is in 9mm Parabellum and is fitted with the accelerator. Both are fitted with artillery Luger rear sights.

An amusing exercise in fantasy fabrication.

[sheepherder]

Tried two more shots, pistols lying flat on gray foamboard...Too late in the morning, the clouds are reflected in the flat surfaces...

[sheepherder]

Originally Posted by Olle

...one thought is that it may look better with a more blocky sight to match the squarish lines of the pistol.

I could try a shortened Mauser tangent sight; I'm putting one on my Luger long-barrel. I have a spare. It would sit higher, so I'd have to change the front sight, meaning re-machining the barrel. And having it re-re-finished.

Too much work.

but I'm sure you're having fun at the same time!

I don't consider it 'fun'; it's more occupational therapy. A bit of thought, a little creativity, some improvisation of resources...A way to keep my wits sharp...Or at least less dull...

A photo tent and a better camera might be helpful...

I have snow 6 months of the year, plus high winds, rain, and changing light patterns from trees losing foliage. My house is surrounded by the trees. A tent is too much trouble. My picnic table (which is only used by sunbathing dogs) is my studio. If I get the energy (plus $$$) I'll get a sheet of plywood and cut it into sections 2' x 3' and paint them light pastel colors for a background.

That sounds like work too. I have adopted Maynard G. Krebs's philosophy about work.

[Olle]

Originally Posted by sheepherder

I could try a shortened Mauser tangent sight; I'm putting one on my Luger long-barrel. I have a spare. It would sit higher, so I'd have to change the front sight, meaning re-machining the barrel. And having it re-re-finished.

Too much work.

Yeah, too late at this point, and just my opinion anyway. Your photoshops are a good way to visualize it, so that's what I would do if I ever get to it.

Originally Posted by sheepherder

I don't consider it 'fun'; it's more occupational therapy. A bit of thought, a little creativity, some improvisation of resources...A way to keep my wits sharp...Or at least less dull...

To me, it's a way to "get in the zone" and it's almost like meditating. You're concentrating on one one thing and one thing only, and everything else disappears. It's a zen thing.

Originally Posted by sheepherder

I have snow 6 months of the year, plus high winds, rain, and changing light patterns from trees losing foliage. My house is surrounded by the trees. A tent is too much trouble. My picnic table (which is only used by sunbathing dogs) is my studio. If I get the energy (plus $$$) I'll get a sheet of plywood and cut it into sections 2' x 3' and paint them light pastel colors for a background.

That sounds like work too. I have adopted Maynard G. Krebs's philosophy about work.

It's not much work at all, it's actually much less work than fooling with makeshift backgrounds. I have one of these, and it takes about 30 seconds to pull it out and put it on the work bench: http://guide.alibaba.com/shop/pbl-ph...g_9957930.html

The greatest benefit is that you have much better control of the glare, so you can take good pictures even in bright sunlight. Just toss a towel over the top, move it back and forth until you get the right lighting, then you're good to go. It takes a lot of frustration out of it.

Can't help you with the snow though... Maybe it's time for you to migrate to a warmer and more gun friendly climate?

[Lyn Islaub]

Nice presentation. Nice work and thx for sharing your expertise. Most of us on this Forum just dream of having the tools and the skill to carry something like this to completion.
Lyn

[sheepherder]

I read Don Voigt's two threads on his refinishing of a couple of Erma .22 sub-caliber adapter wooden storage boxes. Since these two 'artillery' pistols are languishing in cardboard boxes, I thought I'd see what I could mill out of a piece of 1" x 6" Pine board.

I have no woodworking tools, or skills, or even a general idea of what I'm doing, so there's bound to be lots of mistakes.

The two top pics are the box bottom being milled with ball end mills and center cutting end mills; the two bottom pics are the box top being milled. I had thought to make a 'mask' with the profiles cut out of a stencil and penciled on the boards, but that idea was impractical, so everything was measured & laid out with a carpenters folding rule.

I was much surprised when everything fit correctly and the two boards matched up flush without any gaps.

Next is to find a long thin hinge and a clasp for the front.

I'm going for the wartime crudely made wooden box look. Easier to explain all the chips and dents.

[mrerick]

Rich, I have enough of a machinist in my blood (my Grandfather was a Swedish machinist) that I would really enjoy group therapy with you someday!

Very nice work!

Marc

[DonVoigt]

Rich,
Nice work, that is exactly what you have to do!

One suggestion for the future, fit the hinge and catch to the blank boxes and then layout and rout
the openings.

Looks like you may not have enough room for some hinges and clasps, or they may come "ugly" close to your cut outs.

You can see what I mean in the picture below.

[sheepherder]

Originally Posted by DonVoigt

One suggestion for the future, fit the hinge and catch to the blank boxes and then layout and rout the openings.

That did enter my mind, after I had milled out the barrel cutout in the bottom. Hindsight is 20/20. But the closest store with hinges is an Ace and their hinge is too wide for where I placed the cutout.

Looks like you may not have enough room for some hinges and clasps, or they may come "ugly" close to your cut outs.

You are right. I should have gotten a 1" x 8" board. After the top was 'done', and the barrel cutout in the bottom was matched, I clamped them together and milled the hinge side and the two ends so there were no overlaps of one board to the other. But still without a hinge.

There's a Rocklers up the road a piece, I got my router bit for my carbine buttplate there. Later this week I'll check for a hinge & a clasp.

I'd like to get the 'scythe' type clasp, that swings into a loop to hold the box closed. My wooden X-Acto knife box had such a clasp, until my last wife took it with her (she made accessories for 'miniatures'...What I would call doll houses).

I could fasten the hinge to the back edges of the 'box'. It wouldn't look WW II-ish, but it would work. I think to mount the hinge inside the 'box' I would have to mill reliefs for the hinge into the edges of the 'box'.

I still have the Lahti to do, maybe I'll get that 1" x 8" board.

Another problem: The board I selected had been stored in an open shed probably all Winter. I selected one that was straight and not warped, but after being in my warm dry house, it curled sidewise. I milled my cutouts so that the two boards 'spooned' when put together, but that's not right either.

ARGH!!!!

Edit: That 1937 Erma military box looks like it could be hardwood. That would be a lot more stable than Pine, and the cuts would be better looking. I'll have to find an online hardwood dealer. Although I do have a couple of 'knick-knack' shelves without any 'knick-knacks', I could sacrifice those...

[DonVoigt]

Rich,
All good and true points.
Just a couple ideas.
-you can mill a common piano hinge to make it more narrow, you have the machine! And you will have to mill relief for the hinge to fit flat.
-the home supply stores around here have very nice oak boards in all sizes- and well cured.
-look for an old hardwood table leaf, at a yard sale or where ever

I've not yet found a latch that didn't look "chintzy", still looking.

[KABAR2]

I want to compliment you on your machine work, very well done! I'm surprised you weren't temped to either slot or add a stock lug to the Nambu ..... of course you realize in 50 years when this information is all forgotten these will be on the Rock Island site as rare prototype pistols....

[sheepherder]

Originally Posted by KABAR2

I want to compliment you on your machine work, very well done!

It's not about garnishing applause. It's about showing what can be done on a budget by a moron with a milling machine. A cheap-ass Chinese piece of sh*t actually. (The mill...not the moron)...

I'm trying to motivate others to roll their own.

I'm surprised you weren't temped to either slot or add a stock lug to the Nambu ...

One model of the Nambu (not the Type 14) used a Mauser-like stock-holster with a telescoping attachment. But the backstrap on the Type 14 is too thin (~.165") to mill a slot like the C96 has. Something could be brazed or welded on but that would destroy the profile and be even more uncomfortable to handle and shoot. So I ditched that idea.

But a Walther P38 could have a backstrap made that would hold the mainspring & guide and have a straight slot. Martz did exactly that with his P38 carbine conversions. I may try that, sometime in the future.

I have about a dozen unfinished projects sitting on my shelves, waiting for stock, or tooling, or just plain money. The Nambu can sit for a while...Maybe years...

BTW, I would be remiss if I did not credit Charles Danner with the refinishing of both of these handguns. Charles draw files, sands, and re-cuts any lettering/numbers as well as any logos that may be diminished by the metal removal. He then rust blues and straws the parts. Great job(s)!

[spangy]

Truly inspirational and a joy to peruse .... Thank You sheepherder.

Beautiful work

[sheepherder]

Originally Posted by spangy

truly inspirational and a joy to peruse .... Thank you sheepherder.

Beautiful work

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