Gonzo Long Barreled P08 Project

[sheepherder]

Most of the excess silver-solder has been filed/milled off, and now I want to check out how to fit the forearm wood. My woodworking skills are minimal, so I'm going to practice on at least one scrap piece of wood before I sacrifice a rifle stock for my forearm.



(51) Scrap piece of 2x4 soft Pine.
(52) Fully inletted and ready to trial fit.
(53) Not bad. A bit oversized, but acceptable.
(54) Closeup of inletted forearm with lug fitted.



Side view of mockup forearm, off and on. Doesn't look like much, does it? Took me about four hours to get it this far. Shame I didn't have a piece of nice Walnut instead of Pine, but them's the breaks. I'll have to mill out the rifle stock donor piece differently, since it won't be squared-off like this nice piece is. I have a couple old sawed-off buttstock pieces, rounded off, I'll have to think up a way to hold them in the vise for inletting.

Dug out a couple of old Walnut stocks from my 'parts box'. Top is 3/4 of an Ithaca Model 37 shotgun stock, bottom is [IIRC] a buttstock for the MAC-10, which I never owned but thought the stock might come in handy [Numrich of course]. I'm just squeezing the buttstock half between two plywood pieces in my vise...It seems to hold it OK. I'd rather I had a squared-off piece of hardwood, but for the little I need, this might work...maybe...



(55) Ithaca on top; MAC-10 on bottom. Mildewed, and Ithaca has a 3/4" hole drilled through it for the bolt.
(56) Fully 'inletted' with metal working end mills. I don't have any woodworking tools. I'm not a woodworker (as will become apparent).
(57) Inletted mockup placed on stripped frame/action. Profile needs to be taken down quite a bit and shaped, but this is just a practice forearm - the 3/4" bolt groove leaves too much gap on barrel sides. Other half of Ithaca buttstock will be Forearm Attempt #1...
(58) 1st Attempt at an actual Walnut forearm. Barrel channel and rear sight cavity have been milled out with a 5/8" ball end mill. This is the other half of the Ithace Model 37 shotgun buttstock, without the 3/4" bolt hole through it.



(59) Fully inletted forearm blank. Came out pretty good, although again, a lengthy tedious process.
(60) Top & side views; wood has yet to be pared down to desired profile. That comes next.
(61) Top view comparing Ithaca bolt hole (my barrel channel) with 1st Attempt barrel channel. The 1st Attempt is ~5/8" whereas the Ithaca bolt hole is ~3/4". Doesn't look like it, but it makes a big difference. I'll continue practicing on the 3/4" channel forearm blank for now.
(62) I've done a bit of mill-profiling on the 3/4" channel blank. Starting to look like a forearm.

My next step will be trying to figure out a way to hold the inletted forearm so that I can file/sand the squared edges. I'm thinking of an aluminum bar that fits tightly into the lug slot and extends beyond the ends. Have to check and see what I've got.

I found an old piece of 1/2" aluminum bar/plate and milled it to be a snug fit in the forearm inletting. Now I can clamp the inletted forearm in the vise for more milling, I'm working on the '1st Attempt' forearm here; the one with the tight 5/8" barrel channel.



(63) Using a 5/8" end mill to cut the 'Schnabel' curl. Also milling the taper on each side of the forearm.
(64) Milling the bottom of the forearm, up to the curl.
(65) Flipped over; scrap piece of aluminum & a shim in forearm, milling the top flat.
(66) Top view showing taper; side view showing profile.

Waiting for new end mills, cutters, and other miscellaneous tooling, so I'm switching over to the rear sight modifications.

[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!