Gonzo Long Barreled P08 Project

[lfid]

really creative work of art - in metal and wood - nicely sculpted !!!

[sheepherder]

I've gone over the text on page 1 and corrected some mistakes and added a few additional remarks. My apologies if some of the composite pics seem to be out of order, especially the forearm machining, but it's kind of a compilation of several of the five forearms showing the milling operations.

I'm quite pleased with the final forearm. Making them all, using metalworking tooling and machinery exclusively, was very satisfying. The final forearm is not an accurate copy of an actual Luger forearm, but it kind of looks like one, if you squint your eyes and stand back a few feet...

Before I stick them away forever, I thought I'd take a group photo of the five forearms that I made for this project. Two I made mistakes on, one was a 'feasibility study', one was just for practicing machine operations, and one turned out OK.

- Far left is the one made from an Ithaca M37 stock [feasilibility study]. Barrel channel was too wide, due to Ithaca attaching bolt.
- Next is a white pine - oddly, this one is by far the best. Everything just came together on it.
- Middle is made from an 1891 Argentine Mauser stock, but I made the curled tip too small. Otherwise, a good one.
- Light colored striped one is made from the 1895 Steyr straight-pull stock. I mis-measured the trigger guard distance and this one cracked when I screwed it to the lug.
- Last one is another 1891 Argentine Mauser stock piece. This one wasn't quite as good as #2 and #4 but it's good enough!

[Jim Solomon]

Very nice work. Thanks for photos of the process. Quite creative.
Jim

[sheepherder]

This will be a rehash of what has gone before, but I decided to experiment on a couple of ideas I had, and take pictures so I would have a record.

I had originally made two barrels for this Gonzo project; after doing ~85% of the longer barrel, I decided to go in a different direction. So, I shelved the second barrel and started a third.

(1) The donor barrel - a Remington 700 barrel in 30-06 caliber.
(2) Turning down the barrel for the FN/Mauser carbine rear sight.
(3) Turning down the 'flange' that bears against the barrel extension ['receiver'].



Continuing operations on the Remington 30 cal barrel.

(4) Turning down the breech stub.
(5) Threading the breech stub.
(6) Cutting the stub to required length; turning relief.
(7) Final fitting the barrel extension to the threaded stub.



Chambering for 7.65 Parabellum.

(8, 9, 10) Cutting the chamber, 1/32" at a time.
(11) Final fitting the 7.65 Parabellum chamber.



Fabrication of the front sight base.

(12) Rectangular piece of steel drilled & tapped 1/2" x 28tpi and mounted in rotary indexing head to mill outer diameter.
(13) Milling the sides of the sight base flat.
(14) Chamfering the front of the base and milling the rear ramp.
(15) Turning down and threading the muzzle for the front sight base.



Now I'll mill the dovetail for the front sight blade.

(16) Cutting the dovetail.
(17) Milling the front sight blade from a piece of 3/8" steel bar.
(18) Blade has been dovetailed and is ready to be pressed in place.
(19) Blade has been squared to size and is being finish milled.



Test fitting the various pieces for fit and visual effect.

(20) Front sight screwed in place.
(21) Rear sight is a slip fit; it will be secured with screws later.
(22) Full length profile view.



Next will be making a keyhole spanner for the front sight base and a set of vise inserts for this barrel.

[sheepherder]

Making the front sight base keyhole spanner, barrel vise inserts, and other small items.

(23) Boring a hole in a chunk of 7/16" aluminum plate.
(24) Milling the slot for ramp clearance.
(25) Spanner in use. Works great! By some stroke of luck (or divine intervention) the sight base is in exactly the right position for tightening to 12:00 position.
(26) Milling Patridge-style notch in rear sight leaf, to match squared front sight blade.



Vise inserts, made from aluminum round stock, 1 1/2" dia & 1 1/2" long.

(27) Faced insert being bored to ~.755", which is the diameter of the barrel just in front of the rear sight base.
(28) Sawing the finished vise insert in half. Cuts will be belt sanded smooth.
(29) A second vise insert is used for the front sight base, as shown in pic #25 above. An insert from another barrel project was the right size, so no other insert fabrication was required. Sight spanner, vise inserts, and receiver insert shown with torqued assembly. Bluing will be the final step.



Next will be a new, longer forearm to match this longer barrel.

(30) I have a piece of some kind of Walnut, 21" x 8" x 1 1/2". Has some defects [the X] but hey, it's what I gots.
(31) Slab has had a 1 3/4" x 9" piece cut off, decked top & bottom parallel, and barrel trench cut with a 5/8" ball end mill.
(32) Trimming ~.200" off each side. Bottom has had a similar amount milled off.
(33) Cutting the coves with a 1/2" ball end mill. Mounting holes were drilled first to hold the forearm to my mandrel/vise fixture.



Next up, I think, will be the bottom angled cut.

[sheepherder]

Continuing work on the forearm. I made this one eight inches OAL. That makes it half the length of the barrel, which looks more balanced to me.

(34) Side milling the bottom of the forearm, using a 5/8" end mill and taking ~.030" deep cuts, ~.080" wide.
(35) Side milling the tapers on each side. Taking about 1/8" taper off. I thought I'd take a couple 'action' shots, just for a change.
(36) Milling the curved end of the brass inlay bar, with a 3/16" concave radius cutter.
(37) Drilling the relief holes for the inlay screws in the forearm inlay.



(38) Switching over to a 3/4" corner rounding end mill to round the bottom of the forearm. Another 'action' shot.
(39) Brass inlay being milled down with a 3/8" end mill to match forearm bottom surface .
(40) Beveling the upper edges of the forearm.
(41) Forearm, brass inlay, and brass attaching screws are finished. Wood has two coats of BLO on it, and I was surprised/disappointed to see how dark it turned out.



Next up is to stamp or cut index marks for the barrel/receiver and front sight ramp/base and barrel. I also want to bevel the muzzle and and crown the bore slightly.

(42) Here's a comparison of the 13" barrel & 6 1/2" forearm and the 16" barrel and 8" forearm. I've seen pictures online of 16" carbines with the short 6 1/2" forearms; they look disproportionate to me. These two combinations look much more proportional IMO.



Finishing up some of the 'little things' that need doing; feed ramp, extractor notch, muzzle crown, muzzle cap bevels...

(43) Using a curved lathe tool bit from Brownell's to cut a radius on the muzzle. I've had mixed success with this, it seems to chatter a lot.
(44) Cutting a 45º bevel on the end of the muzzle cap. I also opened up the hole a bit and beveled that as well.
(45) Cutting the feed ramp with a 10mm end mill.
(46) Different fixture; cutting the extractor notch with a 3/32" Woodruff keyway cutter followed by a 3/16" Woodruff keyway cutter. Sharp edges will be rounded off with a needle file.



That should pretty much finish up machining operation for the 16" barrel and forearm. I'll be looking for a mailing tube to send it off for blueing. I haven't decided if I should get a separate toggle assembly for this upper, or just use the 13" toggle assembly. Really doesn't matter, I suppose. I can only use one at a time. If I was to get a separate toggle assembly, I would probably be tempted to build another long-barrel frame assembly to go with it...

[sheepherder]

In another thread, Schutzenbob is building a Sharps-Borchardt with a forearm dovetailed to the barrel. That sounded interesting, as it would allow you to use a long barrel w/forearm on any Luger without the mounting lug for the forearm. I have one more Remington 700 30-06 barrel, so I'm going to make a long barrel with a forearm dovetailed to the barrel, somewhat like the Luger artillery rear sight dovetail. Long enough to hold two forearm attaching screws. And I'll make the inletting at the rear of the forearm wide enough to allow it to recoil over the frame.

Here's the start...

(1) Remington 700 barrel in 30-06 caliber.
(2) Turning down the breech end to the OD of the Luger barrel flange and then turning that down to the ID of my 1896 Swedish Mauser carbine rear sight. The two black spots are the OEM Remington rear sight tapped mounting holes. I'll be using them to attach my sight.
(3) Sight slipped on for final fitting.



The sight is from an 1896 Swedish Mauser carbine. I like the look of it, although like all Mauser sights, it is incredibly optimistic.

(4) The Swedish Mauser carbine sight, same ID as pretty much all Mauser sights.
(5) Threading the breech end of the 30-06 Remington 700 barrel to Luger specs.
(6) Cutting the breech stub to length, relieving the rearmost end of the thread.
(7) I've decided to make my barrel band/muzzle cap/front sight blade all out of one piece of steel. In the past, I've milled/turned the FS band out of steel rod and dovetailed the blade into it. This time I've drilled & tapped a piece of 1" key stock for the 1/2" x 28tpi barrel thread I'll be using, and the blade will be integral. At least, that is Plan A.



Next I'll be threading the barrel/muzzle for the muzzle cap/band/sight base, and milling the cap/band/sight to shape.

(8) These three pics show the muzzle being turned to diameter, threaded 1/2" x 28tpi, and the steel block from pic #7 above fitted to the barre.
(9) This is the steel block being milled in a rotary indexing head. I had the thought that milling it would be faster than band-sawing the block to the rough shape & size. I was wrong. It took much longer. Next time I do a similar part, I'll band saw it first.

First pic is the rough rounding of the block, second is the finished band, third is the muzzle of the cap sized to the same OD as the end of the barrel, before the threads.



Next will be milling the band flat on each side and then milling the blade.

(10) Milling the sides of the blade/base flat.
(11) Milling the top of the blade down to equal the height of the rear sight folded.
(12) Milling the blade itself down to ~.120".
(13) Muzzle cap/band/blade shown on barrel for effect.



I had to fabricate a new muzzle cap spanner; the pics are of it being milled out of 7/16" x 1 5/8" 6061-T6 aluminum bar. When it was done, I assembled the barrel, rear sight, barrel extension ['receiver'], and muzzle cap/band.

(14) Boring out the aluminum bar, milling a .350" slot, and test fitting the spanner and muzzle cap. Assembled unit shown for effect.



Next I will 'slope' the blade forward. I also need to mill the rear sight 'V' to a square Patridge style aperture.

[sheepherder]

More little stuff, milling the muzzle cap and the rear sight.

(15) Milling the ramp on the rear of the muzzle cap/band.
(16) Milling the 'slope' on the front sight blade.
(17) Milling the 'Patridge style' notch on the 1896 Swedish Mauser carbine rear sight leaf, folded section.
(18) Milling the 'Patridge style' notch on the slider.



Next on the list is to cut the extractor notch and the feed ramp.

But first, I'm itching to start on the forearm.

(19) Here I took time to make a much-desired modification to my receiver wrench - an extra locking lug recess in the handle. It came with the recess in the cap, but I level my Luger barrels using the front sight, so having the handle sticking straight up is awkward. Now I have 180º capability.
(20) Here's my piece of Walnut. My neighbor told me it is 'Black Walnut' and that is why it turns so dark with BLO. I dunno, I'm not a wood person...
(21) Here I've milled out the main channel for the barrel and rear sight base.
(22) I'm using a Woodruff key cutter to mill the slots for the frame rails. The barrel with forearm attached with recoil ~.3/8" over the frame. Right now, it all fits; I just have to lengthen the slots a bit.



I am finding it difficult to visualize the forearm in action and transfer the minds-eye image to the forearm. I had thought I would taper the barrel channel to match the barrel but the math was really confusing me. The masking tape in #21 shows what the OD should be at those points..

[sheepherder]

I got the first 16" barrel back from the bluer today. It's all together, and looks good!



Here's a comparison of the finished 13" and the finished 16". The 13" has the 6 1/2" forearm; the 16" has the 8" forearm. The 16" has the full length FN Mauser carbine rear sight; the 13" has the shortened FN Mauser carbine rear sight.



Work on the second 16" barrel with the Swedish Mauser sight continues.

[DonVoigt]

Rich,
thanks for taking the time to do the 'how to' pictures and posting them.
Great info and i know it took a LOT of time and effort.

The end result looks super.

[sheepherder]

Work on my second (or is it third???) 16" barrel continues. If you've read through page one and this page up to here, then this is all a repeat of what has gone before. I have done a few things differently, and I want to preserve them for future reference, so please bear along with me...

(23) Cutting the rear of the forearm. I've cut the 'scallops' so that they will recoil over the frame ~3/8". It makes the forearm wider, but the side profile will be similar.
(24) Now that the forearm has been fitted to the barrel and inletted to clear the frame, I need to locate where I will cut the dovetail for the forearm lug. To do that, I need to finish off the chamber and fasten the barrel to the receiver for the last time. Here I'm chambering it for 7.65 Parabellum.
(25) Cutting the feed ramp.
(26) Cutting the extractor notch. I use two Woodruff keyway cutters, and smooth the interior corners with a triangular file.



The barrel has now been screwed into the receiver and torqued to place the rear sight at exactly 12 o'clock relative to the extractor notch/feed ramp.

Next will be locating the screw holes in the forearm and then milling out a slot in the barrel for the dovetailed lug.

(27) Milling the slot for the brass inlay.
(28) Side-milling the bottom of the forearm; final cut.
(29 & 30) Milling a flat for the forearm attachment lug, and milling the ends for a 60º dovetail.



I'll make the lug next, with a 60º chamfer on each end for a ~2 1/8" long x 3/8" wide dovetailed lug.

(31) Milling the lug with a 60º cutter.
(32) Forearm lug drilled & tapped for attaching screws.
(33) Side milling the forearm taper.
(34) Milling the brass inlay for the forearm.



The barrel is completed. I'll fine sand the barrel itself to make it shinier. Rest of the remaining work will be on the forearm wood and the brass inlay.

Woodworking - I hate it. I hate sanding. So most of my woodworking will be done with metalworking tools.

(35) Using a corner-rounding end mill to round the bottom of the forearm.
(36) Using a tapered burr to relieve the top of the forearm.
(37) I'm rounding the tip of the forearm on my belt sander. I've left this to last because in the previous forearms, I've chipped the curl when milling the sides first. I had to make a wedge-shaped jig to hold the forearm square with the belt. Next, the part I hate - finish sanding the wood to minimize tool marks.
(38) This shot is to show the assembled barrel & forearm in battery and under recoil. You can see that the fixed forearm, with its carbine profile, recoils past the trigger guard. I had wondered if this would pinch the shooters trigger finger, but unless the shooter has fat sausage fingers, it doesn't hit the finger. In fact, I couldn't release the trigger quickly enough to even be close to the forearm tang.



That pretty much wraps it up for the fixed forearm and long barrel. The barrel will go out for bluing, and I'll put a couple coats of BLO on the forearm. The brass inlay also needs a couple thin cuts to make it level with the forearm.

Originally, I had worried that I would need to screw the dovetailed lug to the barrel so it wouldn't come loose. It has to be removable, as the rear sight needs to move past it on assembly. But while fitting the forearm wood to the barrel, I realized that the dovetail lug holds the forearm tight to the barrel and the sides of the forearm hold the dovetail lug from moving. It's a non-problem.

Here's a couple pics showing the completed barrel/forearm combination, with and without frame assembly.





I'll replace those pics with the 'finished' pics when the barrel comes back from being blued. Hopefully, I can take the pics outside.

[sheepherder]

Cleaning up some of the odd operations that remain.

(39) Milling the brass attachment inlay flush with the forearm. I'm actually milling it down to ~.004" from the surrounding wood. There is a .004" shim under the brass inlay.
(40) Heavy coat of BLO applied to the wood. Let soak in for 10 minutes, wipe off excess, and let dry. Another coat in an hour or so. Objects in foreground are the dovetailed steel lug, brass inlay, brass screws, and that .004" shim.



Here's two additional pics. I was trying to show how the fat barrel-mounted forearm is wider than the lug/frame mounted forearm.

This last 16" barrel and forearm was just an exercise. I don't expect it to win any beauty contests. I just wanted to see how it would look, and if it could mimic the profile/look of a 'traditional' carbine.

[sheepherder]

I got my faux 'carbine' barrel assembly back from the refinisher; it looks good!

Forearm is about as done as it's going to get. Everything has been assembled and function-tested, no problems.

To reiterate - The forearm mounts on the barrel and recoils over the frame. That makes it fatter than a 'real' carbine forearm, but the profile is similar. No modifications to Luger frame necessary.

Here's the finished product -

(41) Finished barrel assembly; blued, chambered for 7.65 Parabellum, notched, ramped, dovetailed, drilled & tapped. Swedish Mauser rifle rear sight, custom front. Original toggle mounted rear sight is lower than Mauser so it does not interfere with new sight picture. Swedish Mauser sight graduated to 1600 meters. It'd be like lobbing a baseball.



(42) Closeup of top & underside of forearm and installed dovetail lug, plus mounting screws. Like all Luger carbines, forearm must be removed to disassemble the pistol. The difference is that my forearms are screw-mounted instead of a tapered wedge.



(43) Closeups of Mauser sight up & down; front sight; and rear views showing hollowed-out wood.



(44) Static and cycled pic of faux assembly mounted on a 1937 Mauser Luger w/Erfurt toggle assembly. Side profile still resembles a 'real' Luger carbine but does not require any modifications to the frame for the forearm.



(45) View showing barrel & toggle train in full recoil. My finger is in no danger of being pinched. I'm 5'11" 195 lbs. If you had fat sausage fingers you might draw blood, but an average shooter won't get bitten.



That does it for my assortment of Gonzo long barrel Luger 'carbines'. Very interesting conversions and very informative to me as far as 'designing' and creating. This thread is too long and takes too long to load, so anything further will go into a new thread.

(Side view of dovetail lug added).

[SIGP2101]

Work of true craftsman, right there. Thanks for sharing.

[cirelaw]

God gave you a unique Gift!!! Its wonderful for you to share it with all of us!!!! Eric

[DonVoigt]

Nice work Rich.
Really nice wood work.

Do you really need those ears at the rear of the fore arm that recoil into the trigger area?
I guess they are essentially cosmetic, as there can be no rotating force to the fore arm.

[Diver6106]

Beautiful work! But does the action jam with the greater weight forward and the design where the fore stock is not mounted to the frame? I guess you can't hold the fore stock or it will impede the recoil action and jam. I'm working on my own carbine with a 16.5 inch barrel and looking for a fore stock and angle piece to mount to the frame.

[sheepherder]

Originally Posted by DonVoigt

Do you really need those ears at the rear of the fore arm that recoil into the trigger area?

No, as you noted, they are cosmetic. I was going for the profile of a carbine.

Originally Posted by Diver6106

But does the action jam with the greater weight forward and the design where the fore stock is not mounted to the frame? I guess you can't hold the fore stock or it will impede the recoil action and jam.

If it was all sorted out with a specific load/bullet/recoil spring, it should function normally. And in theory, the bullet should have left the barrel before the cannon recoils, so (again in theory) whether you still have your hand on it or not wouldn't matter.

I'm big on theory.

[DonVoigt]

I could never get a 16" .30 barrel to work in SA fire.

I think it would require an auxillary spring to close the toggle; and for sure if you were holding the handguard on the one above, it would make a big difference - not a theory- I've done it when struggling to try to get my 16" bbl to work.

[sheepherder]

When I first started that particular build, I had it in mind to make it a 'pump action' repeater. A sliding forearm with a rod going up to the toggle. The toggle would stay closed until the slide action opened it. But I got hung up on how to lock the action closed when firing. I had thought of a button/bar that would engage the frame until pressed then it would unlock the slide. Pretty much like a pump shotgun.

But I got too engrossed in the rest of the build...It took on a life of its own...

It wouldn't have looked like a Luger carbine either, even from the side. Think of one of those old .22 Winchester pump action rifles. With a long bar going from the slide up to the toggle.