Building a Barrel Rifling Machine

[303Guy]

I've had this idea on hold for some years now but all the talk about straight walled 41's and 375's is getting me interested in doing my 375 Lee Enfield project.

My plan is to build an attachment for my lathe. I had been thinking of a reduction gear box driven off the lathe power screw shaft that would rotate the rifling cutter at the correct rate while the same power screw is driving the head and of course holding the barrel in the chuck.

Any suggestions, better ideas, pitfalls?

[jbunny]

heres some pics of my lathe att rifleing rig. u remove the tailstock and this clamps on the ways. the barrel blank goes through the spindle shaft and out the back. the twist
is whatever u give the 1/2 square stock. i did 2 barrels useing the single hook cutter.
u realy got to know what ur doing with the hook cutter. i then made a scraper cutter
and way easier to make and use.
http://i138.photobucket.com/albums/q273/MOUICH/barrelrifleingattachment.jpg
http://i138.photobucket.com/albums/q273/MOUICH/barrelrifleingattacment.jpg
http://i138.photobucket.com/albums/q273/MOUICH/barrelrifleingattachment3.jpg

[longbow]

I have been thinking on the same thing for a while myself though my goal is rifled choke tubes for shotguns. I want deep wide grooves, narrow lands and slow twist for round ball or "square" slugs.

I looked up a variety of methods of rifling. More than one way to skin a cat!

Take a look:

http://www.scribd.com/doc/3602969/firearms-How-to-Build-the-Antique-Rifling-Machine
http://www.network54.com/Forum/576299/thread/1202627982/A++Few++Boring+and+Rifling++Machine+Designs
http://toadhallrifleshop.com/wooden-rifler/

Lots of info in the second link.

I got the Toad Hall book which has instructions on making the traditional wooden rifling bench. I thought I would adapt the techniques using modern materials.

Another project that awaits time and energy!

Another simple option is to use a barrel with the correct twist rate, cast a slug (or swage) to fit the rifling, attach a steel rod to carry the cutter and use that barrel as a rifling guide. Clamp both barrels in line then run the slug/rod/cutter back and forth to cut the rifling in the new barrel. Indexing the cutter can be done by removing the guide slug and rotating one groove at a time as you go.

Of course large bore for the guide barrel is beneficial in that there is more room to drill and attach the steel rod.

jbunny has yet another idea that works and is pretty simple to put together.

If you make up a machine that works, remember to post photos!

Longbow

[W.R.Buchanan]

OK now these articles were interesting.

I especially liked the machine with the sine bar rotation mechinism, as opposed to the twisted rod style of twist mechinism.

Pretty cool stuff.

Randy

[bob208]

the machine i have has a sine bar set up for zero backlash.

it is easier to build a machine then to adapt a lathe to do it on.

the other machine i am working on is a deep hole drill.

[uscra112]

Love it! The piece of rebar is a bit "agricultural", but the rollers on the twisted bar is a stroke of genius.

[jbunny]

many moons ago, 50 years or so, i just remembered the first barrell that i rifled.
i had bought a 48 in octagon smooth bore 40 cal barrel blank from dixie.
all i had for tools was a 1/4 in hand drill and a little buzz box welder and the only knowledge on guns was that they whent bang. i cut a square peice of plate the same size as the 4 oposite sides on the octagon barrel. i welded 4 ears on the sides
on this plate. the ears alowed me to clamp this on to the barrel. in the middle of this plate i drilled a 1/4 in hole. i then made this hole into a 1/4 square hole. i took a 1/4
in key stock a bit longer than the barrel. i slid a peice on pipe or tubing over the key
stock to keep the key stock straight while i twisted it. i made a slot in a peice of tubeing
and attached it to the key stock. i put a peice of rubber in the bottom of the tubeing
slot. i would break a peice of file off and squeeze it in the tubeing slot and start it
in the barrel and then it was walk back and forth. it worked. u get the idea. now i would use a peice of carbide saw tooth silver soldered on to a scraper cutter.
for one or 2 barrels it would work.
cheers

[arjacobson]

NICE work-Always wondered how they did that

[John Taylor]

If you want to use an old lathe the easiest way is to use cable and a wheel with the circumference the same as the twist you want. The two ends of the cable are attached to the carriage, ( one end may have a spring to keep things tight). A couple blocks (pulley ) at the ends of the lathe bed. As the carriage is moved it turns the wheel which is attached to the barrel. You will need some form of indexing on the barrel for the number of grooves you want. Changing the rate of twist is as simple as changing wheel size and adjusting the cable.

I went with a sine bar on my machine. After looking at my Lathes I realized they did not have enough travel for the longer barrels I wanted to do. My machine has 52" of travel and can do a 48" barrel.
http://i95.photobucket.com/albums/l132/johnptaylor/IMGP1480.jpg

[303Guy]

Thank you all. This is very interesting. Those wooden barrel rifling machines are amazing.

That cable idea could be just the ticket, thanks. I could adapt the idea to a chain and sprocket and use that as the indexing system. Only the smaller drive sprocket would need to be changed for different twist rates but I'd start with the twist rate I want and probably never change. Well, maybe two twist rates, one being a 1-in-10 for 'refreshing' rusted out 303 Brit bores to a slightly larger calibre.

I am thinking that because the the carriage is driven off the chuck shaft, I would be setting the twist rotation as a difference between the chuck and the cutter. I would also be wanting an oil injection system and catching on the other end.

[303Guy]

The next question is how to make the rifling cutter?

[John Taylor]

If you will excuse my crude drawing. The cutter box is made from a steel that can be hardened and ground to a smooth finish with a tool post grinder to get a size a few thousandth smaller than the bore. Cutter is HSS and sometimes has a carbide cutting edge. Wedge is hardened and smooth. Spring allows the cutter box to go back through the bore without dragging the cutter against the bore hard enough to damage it. Small spring on wedge keep the wedge from following the cutter on the return stroke. The rod or shaft is held to the cutter box by a pin but could also be threaded. I bore a hole through the cutter box and thread for the adjusting screw before hardening then use carbide to cut the opening for the cutter and grind to proper OD. If the opening for the cutter is cut before hardening the box may warp more than can be trued up with the grinder.
http://i95.photobucket.com/albums/l132/johnptaylor/cutterbox.jpg

[Randy in Arizona]

So let us know when you start re-boring and rifling barrels.
I want an old 03 barrel rebored to 35 or 40 Whelen.

60

[deltaenterprizes]

Guy Lautard the author of "The Machinist's Beside Reader" series has a tape on how to build a rifling machine.
There is instructions on the "Practical Machinist" site in the gunsmithing section

[303Guy]

Thank you, John Taylor. I could almost make one of those (I think). Nothing wrong with your sketch - better than I could have done.

How does the box behave at the end of the bore? Does it cut true right to exit or do I need to trim some barrel off?

Can one make a broach that will 'refresh' the bore to a larger diameter?

I'm not expecting be able to produce a match grade bore with my first attempts. I do plan on finishing with fire-lapping and do not expect to achieve a specified diameter. The idea is to rifle a bore, ream the neck and throat then make a boolit to fit. If I can pass on to a higher level of proficiency then I'd be very happy indeed. I'm well aware of the skill levels involved in craftsmanship and even more aware of my own limitations. But my enthusiasm has gone up a few gears. (I am an apprentice all over again! It was fun being an apprentice).

[John Taylor]

John Taylor has been doing this work for many years and is one of the top cut rifled barrel makers.

I am thinking of paying him for a tutorial, he is only about 100 miles from where I am sitting.

I don't consider myself one of the top cut barrel makers. I'm one of the late comers and am still learning what works and don't work.
I have found out that rust pits in old barrel can be a lot deeper than a person would imagine. Rust is much harder than the original steel and can dull cutters and reamers very fast.
Some metals cut smooth and others do not. I still have not figured out how they got a smooth finish on the old Winchester nickel steel, maybe the age of the metal makes a difference. If only all steel would cut like 12L14 then I would be very happy.

I am always pleased to meet others that are interested in machine work and barrel making. I have even visited other shops to see if I could learn more. Last visit was to Delta gun shop on the other side of the state. Delta/ clear water reboring bought out LaBounty reboring several years ago and does very good work. Their machine is run with hydraulics while mine is strictly mechanical. If I were to build another machine I think hydraulic would be the way to go.

[Tokarev]

Did anyone try button rifling?
I am thinking of making button cutter out of a round carbide insert and pushing it thru, thus creating all groves at the same time. Several of this incrementally should allow to create nice smooth rifling w/o having to use too much pressure on the pilot and having to utilize HSS pilots.
Right now there is a project gun where I would have to re-rifle to a slightly larger grove diameter, by 0.01", where this technology could be helpful.

[303Guy]

Do you perhaps mean broach? A button doesn't cut - it swages.

Have a look at this link.

http://firearmsid.com/feature%20articles/rifledbarrelmanuf/barrelmanufacture.htm

The button rifling machine may be simpler and easier to build but you would have to buy the buttons (they say they are relatively cheap) but accuracy would be easier to achieve with cut rifling although more work. And you can't button rifle a profiled barrel.

[Tokarev]

Broach is the right word, thanks for correcting and educating me, appreciate it (as English is not my 1st language, not even 2nd).
As many inserts are available in .375 and .50, I was thinking of using those for my projects.
It should be fairly easy to grind the cutting surfaces to any number of groves using an indexing head set at the right angle and toolpost grinder with diamond wheel.
Considering that many 38 cal guns have 6 groves, indexing a broach for grinding should be also very simple task using a length of hex stock in a vise or chuck.

At some point I was considering a ghetto rig where a round file ground at the spot which has the right diameter would be a broach, but then decided not to as the files are not very uniform in shape.

[303Guy]

I have thought about making a broach cutter. I suspect it would be a lot easier to make several broaches with one stage cut each so as not to have to contend with getting each stage at the right position. These could then be set in a unit or pulled through individually. Getting them aligned individually could be a bit tricky. Maybe not.

[303Guy]

Is there any reason why the cutter should have a curved profile?
If it was flat across the top it would have to remove less material and would produce a semi-polygonal barrel.

[John Taylor]

Is there any reason why the cutter should have a curved profile?
If it was flat across the top it would have to remove less material and would produce a semi-polygonal barrel.

Use a wide enough cutter in a 6 groove and you end up with a Whitworth barrel.
http://i95.photobucket.com/albums/l132/johnptaylor/Whitworth.jpg

[John Taylor]

Broach cutter, http://www.nij.gov/training/firearms-training/module04/fir_m04_t06_06_a.htm