Gonzo Long Barreled P08 Project

[sheepherder]

I'm using the M24/30 FN Mauser carbine rear sight but I'm going to shorten the sight leaf. I found out the hard way that it is hardened. Anyway, after cleaning up pieces of broken end mills, I managed to use a Carbide end mill to mill the end and pivot slot of the sight leaf.



(67) Slot is already milled; milling end down.
(68) Shortened sight leaf on left; original sight assembly on right for comparison.
(69) This is why I hate micro-machining. I can barely see what I'm doing [which is milling .014" off each side of the pivot ears] and I can't get any feedback from the big heavy toolholder/vise/table feed. This is a 1/8" Carbide end mill.
(70) Another part I hate: Filing the square-cut ears round. My files are barely hard enough to cut the hardened sight leaf. Lots of filing and fitting; I want it to work, but also minimize the gaps. This ain't no work for an old man.

Next I need to cut the FN carbine sight ramp down to match the shortened sight leaf. This is a complicated procedure, involving calculating the bullet weight & shape, the powder charge and powder composition, the barrel length and rifling twist, bullet drop in meters, the curvature of the earth, local variations in gravity, Pythagorean theorem, Sine, Cosine, Tangents...Ah, screw it. I'm just going to make a flattened ramp.



(71) Milling down the back of the ramp to match the height of the barrel extension.
(72) The FN Mauser spring is way too strong for my taste; it's ~1/4" wide x .040" thick...so I dip into Brownell's flat spring assortment, the thinnest is .030", so I'll use that.
(73) The Brownell's flat spring stock is .500" wide, so I mill it down to ~.025". I clamped it to a piece of scrap aluminum.
(74) Finished spring shown next to FN Mauser spring. Next is to harden it.

I have other things going on at the same time as I work on this; some use different jigs/fixtures/vises, so I'll be jumping around on the machining...

I'm going to mill the front sight base down and cut the dovetail. I've clamped the barrel assembly between plywood boards to get a 'soft' clamp, and use a reinforcing rod in the bore just to be safe.



(75) Barrel/sight base is leveled and squared; ready to cut down.
(76) Sight base has been shortened/milled ~.250".
(77) 1/8" x .100" slot milled in center for dovetail.
(78) 40º dovetail cut into sight base, .100" deep. It is .197" wide at base.

I'll be making a sight blade for it next. I'm debating making it out of Delrin or steel...I may do both. The Delrin is quicker to make and can be slightly wider in the dovetail since it has some elasticity, which would make it easier to adjust and also stay fixed in position...

I've sawn a blank out of a piece of scrap steel. This will be the front sight blade.



(79) Milling the bottom of the steel blank.
(80) Milling the 40º dovetail.
(81) Sight blank has been pressed into the dovetail in the barrel. Now I am milling the sides flat and level with the front sight base.
(82) All four sides milled flat and level. I hate machining anything this fragile. One mistake trashes hours/days of work.



(83) Milling the sides of the sight to form a blade .120" wide. Using a radius end mill.
(84) Milling the sight blade at an angle to mimic the Finnish front sight blades used on Finnish Lugers and Lahtis.
(85) Mockup of barrel assembly and unfinished forearm. It looks odd.

[sheepherder]

To all interested members who have wondered if this project has died, it has not. It is temporarily on hold until such time as finances and interest resume.

A member of the other forum approached me about a project that ended in a major disaster some years ago. He wanted a 9mm Walther P1 barrel liner removed and a 30 Luger stepped liner installed. I did a test barrel and it worked out very well. I then did two more and managed to burn out a set of HSS drill bits and a reamer. I upgraded to Cobalt and the next one turned out quite acceptable. I've done several more. Still waiting for a review.

[sheepherder]

...Sometimes, it just won't work...

I thought it would be neat to make my P-08 rear toggle knobs 'dished', like the M1900 toggle knobs. So, I took measurements from side-on and top-on photos and figured out that the 'dishes' were cut 10º from the vertical axis. I also figured that to give me a straight-in cut with my end mill, I need to angle my mill vise 16 1/2º from the horizontal axis. My vise is adjustable, so that took care of the 16 1/2º, and I made up a fixture to hold the toggle at the required 10º [Pic below].

I had previously test-fit various shot glasses, jelly jars, lids for whatever I had that used lids, and determined the diameter of the M1900 dish to be 50mm/~2". My biggest end mill is 1 1/2", used to mill off flash on AR-15 lower receivers. Anything bigger would run several hundreds of dollars, which I wasn't eager to spend for 'dishes'. The 1 1/2" end mill would have to do.

When I got it all completed and set up, it didn't look right. After many years of machining, I have a rough eye for what I am doing. This wasn't right.

It turns out the M1900 toggle/knobs are .150" wider than the P-08 knobs. That threw my straight-in measurement off. I'd need to increase my angle. But then the dish wouldn't be right - the cutter is too small for the narrower knobs. The dish wouldn't look right.

I could mill the dish flat, instead of concave. But that's not right either.

In the end, I shelved the 'toggle dishing project' due to lack of tooling. A few days wasted making the fixture and taking measurements.

Sometimes you eat the bear...Sometimes the bear eats you...

[sheepherder]

First pic -

While pawing through my tool collection I noticed I had a 1 1/2" carbide tipped dovetail cutter left over from some obscure one-time project...So I decided to have another go at dishing the toggle knobs...

The toggle chosen is one left over from some other project <sigh>. I clamped my 'fixture' in my mill vise and 'bored' the toggle dishes. Time consuming and fairly apprehensive, as I had visions of carbide inserts flying around the shop...

But it turned out OK, machining-wise. Still the wrong diameter, and leaving enough metal for the rail contact surface didn't allow much to be machined off, but at least the concept is proven.

I guess that the bear and I are about even on this one.

Second pic -

I was contacted by a forum member who was interested in a 'dished' toggle, so I ordered a carbide shell end mill cutter plus arbor. It should be in shortly.

The 2 1/2" Carbide fluted shell end mill came in; I finished my 'prototype' P08 dished toggle...

Very slow milling; 10º angle from horizontal; plunge milled. I retained the ~.156" contact patch for the frame ramp. The arc of the scallop is not as great as an M1900 due to the M1900 being .150" wider in the knob area.

Came out OK; there were a few tool marks but sanding with 220 wet-or-dry wrapped around a suitable mandrel took them out pretty quick.

Visually not as impressive as the wider M1900 toggle, but it's different...

[sheepherder]

Back to working on the long-barrel Luger again.

Getting the parts ready to be shipped off to be blued. Toggle and rear sight are now done; nothing left for me to work on except forearm.

(86) Cutting the Patridge-style notch in the Mauser rear sight leaf.
(87) Milling off some of the rifle graduations
(88) Making a fixture to hole the forearm so I can file/sand it
(89) Milling a slot in the forearm for the brass inlay to fasten the forearm



I don't have any woodworking tools to speak of, and I don't have a bench or 'pony' to clamp work to, so I have to make up some kind of fixture to hold the forearm while I file/sand it. I made one out of aluminum bar, need to fasten the ends somehow.

(90) Milling a piece of brass for the forearm inlay
(91) Inlay fitted to the forearm slot
(92) Inlay milled down and drilled & counterbored for the attaching screws
(93) Milling the 'coves' in the forearm, using a 1/2" ball end mill



(94) Milling the other 'cove'
(95) Milling right side flat, in a elliptical shape
(96) How that flat looks
(97) Test fit on frame

[sheepherder]

Trying to do as much machine work on the forearm as possible.

(98) "Blending" the brass inlay with the forearm bottom.
(99) Using a 1/2"R corner-rounding end mill to round the bottom of the forearm. This is my test piece, and it actually turned out quite well (surprisingly!).
(100) I'm doing a lateral move now. I'm OK with the forearm I have so far, but there are always different ways to achieve the same end, and I want to explore a couple of these. I'm trying to use my machine tools as much as possible. So, in this pic, I'm corner-rounding the Pine forearm I used as a test piece and tapering the corner at the same time.
(101) Now I'm using a straight 3/4" end mill to side-cut the forearm to taper it from rear to front by 1/4" total [1/8" each side].



(102) I noticed I have some kind of burr or rasp or whatever that has a taper to it, so I'm experimenting to see how it would work on the top of the forearm, to help give it the 'rounded' cross-section that the Luger forearms seem to have.
(103) Here's a shot of the semi-completed Pine forearm. Besides final sanding, the only real area that needs more work is the 'Schnabel' tip. The corner-rounding end mill couldn't go full length, so I have to figure out some way to blend in the curve. I may use my rotary indexing head...
(104) Woohoo! Got all my metal pieces back from the refinishing. All blued except the 6 pieces at the bottom; they have been strawed. Excellent work!
(105) Assembling the mainspring in the frame. Frame clamped to mill worktable so it won't move, and cotter pin puller used to compress spring. Works great!

[sheepherder]

I'm still contemplating on how to form my forearm, so in the meantime I decided to clean up my workbench of projects that have languished over the last couple of years...

The first pic is an 80% M1911 with a Bo-Mar Tuner Rib attached. The slide is a Numrich item while the 'parts kit' came from Sarco. There's a couple aftermarket and OEM Colt parts thrown in for good measure. Haven't shot it yet; no 45 target ammunition available.

Second pic is three Luger-style barrels. The top is an original Luger M1900 7.65mm barrel which was purchased from a forum member and was found to be 'squished' .020" in the middle, probably from being incorrectly [wrong or no tools] removed. I was able to obtain a ground drill blank in the correct size and slowly form it back to round shape with a planishing hammer. That left some marks, along with the 100+ year old nicks & scratches, so I used Ithacaartist's method of filing it on a lathe, insread of my usual single-point cutting. It worked out surprisingly well.

Bottom barrel of the second pic is a 1916 Bohler barrel included for comparison purposes. It's my 'control' barrel.

The middle barrel is a 3" 9mm Green River blank which I tried to profile to 'pocket Luger' shape. I couldn't find anyone who would measure their 'pocket Luger' barrel (which I am told was made from a shortened & silver-soldered Navy barrel) so I tried to take the measurements off a picture or two from PIA, Simpsons, and this forum of the original 'pocket Lugers' (not to be confused with Georg Lugers 'baby Luger"). I'm happy with the machine operations but somewhat disappointed with the actual profile. It looks awfully stubby. I understand that most later 'pocket Lugers' are made from shortened P08 barrels, but was the Navy barrel really so thick???

Posts here state that the Luger 'Fat Barrel' and 'Cartridge Counter' Lugers had the same dimensioned barrels used to make the shortened 'pocket Lugers', so that is what I used for my dimensions. Vernier calipers on a photograph; not the easiest (or best) way to get dimensions.

Eventually, I'll finish up cutting the sight dovetail and the muzzle, and install it on a barrel extension for looks. It's already indexed and chambered.