Progress on rifling machine and rifled choke tube!

[longbow]

Well, like the title says, I am making progress... slow but progress.

My rifling machine (I use the term loosely) is finished or at least the prototype is finished. It is a modern take on the old style wooden rifling benches but smaller and made of steel. I will post some photos after I neaten it up some.

In any case, it works! I started rifling a piece of 3/4" pipe as a trial run. I learned a few things and I believe I will modify the rifling head.

101190

I used the old style wooden rifling head with inletted cutter. Not going as well as it might though it does work. The cutter is a slip fit into the inletted head and I used paper shims to raise the cutter but it keeps coming loose so I think I will change the design slightly and add a shoe under the cutting head then shim the shoe.

In any case, the goal was deep wide grooves and narrow lands. My trial run on 3/4" pipe has turned out not bad though rifling is probably only about 1/2 depth right now. Grooves are about twice as wide as lands. I may take it all the way as I am still learning so I might as well learn on pipe.

After I practice a bit then modify the cutter head I will pick up some 4140 to make choke tube, barrel adapter and muzzle break.

I have to say that dragging a rifling cutter through a barrel (short as it is) is work! Not sure how many strokes I have done but I was running from 25 to 100 strokes per groove (depending on cutter "bite") then re-shimming and run around again. So far I have used about 15 paper shims so LOTS of strokes and still only half there.

I may modify the cutter some too. I think it has too much surface contact so fewer teeth should increase cutting edge pressure and metal removal ~ and work, but less strokes.

Longbow

[Dryball]

Very interesting. Check out youtube. There's a series on there called the Williamsburg gunsmith. Shows him building a flintlock from scratch and it focuses quite a bit on the rifler.

[bikerbeans]

LB,

I like your project! Pretty soon you will be making full length rifled slug barrels.

BB

[AlaskanGuy]

I cant wait to see how this turns out LB

[texassako]

Pretty cool! I have Guy Lautard's DVD's on Bill Webb's rifling machine and most of the materials in a box under the bench waiting for space and time to complete it. Yours sounds simpler and not as large, and I would like to see a photo of the cutter if possible.

[sirsloop]

Looks like a fun project... What are your end goals?

[Reg]

Looking good. Would like to see more, the machine, the head and how you do it.

[Hogtamer]

LB, I'll send you a sawed-off barrel smoothbore 870 barrel to rifle so I can be first in line when you go in business or just need a guinea pig to test one on!

[longbow]

The goal... strange as it may sound to some... is to have a modern Paradox gun that will handle shot and slugs well to 100 yards or so.

I have tried with smoothbore but I certainly have not found any magic bullet/boolit/slug that performs consistently out to 100 yards giving dependable groups of under 6".

I am quite happy with my smoothbore round ball (and some slug) loads to 50+ yards but at longer range groups do get significantly larger.

I know, it would be easy if I just got a fully rifled barrel, but I like smoothbores and I like the idea of a Paradox gun. I just can't afford H&H's prices.

In any case, it keeps me off the streets. A guy needs a hobby right?

If it all works out then I would look at making up a side by with rifled choke tubes to create a poor man's big bore double rifle but also with a simple change out of tubes it would handle birdshot or buckshot well too. What's not to like?

Not much innovative about my rifling machine and it is all built out of old scrap I had laying around. In fact one piece was made form a bolt I found laying by an old (like 100 years old) rail track. it was covered with heavy rust but was the right size to make a thrust washer out of.

Basically it follows the old style wooden rifling bench systems but I used a twisted square bar for a worm. The cutter head is wood as well, inletted for the cutter. I am having problems with the cutter working loose though so either my woodworking skills are lacking some or the wood I used is a bit soft. So far that has been the only problem and that is easy to fix.

I will do some more rifling to increase depth and play with the cutter head some then neaten the thing up a bit and take photos. Or if the mood strikes me I may just post what I've got crude as it is.

And no to bikerbeans! It would be much easier and probably cheaper to just buy a rifled barrel or an H&R Ultra Slugger if I wanted a fully rifled barrel. Even this little choke tube is WORK to make. It makes a guy respect the old timey gunsmiths that rifled full length muzzleloader barrels let me tell you!

Oh, I should add that I am making my own choke tube because I want wide deep grooves and slow round ball twist. My current twist is as close to 1:72" as I could gauge twisting the bar using a protractor. Actual round ball twist for 12 ga. is 1:110" though I have read that the Paradox guns (at least some) used faster twist but it was deep aggressive rifling unlike modern rifled choke tubes.

So that's all I've got for now.

I will post more when I've got something.

Longbow

[W.R.Buchanan]

LB: Earlier you commented on how much work it was to do one groove. I have had conversations with the guys at Krieger who use WWI vintage rifling machines to turn out some of the finest barrels known to man.

A typical barrel with grooves .004 deep requires 40 passes per groove. IE .0001 per pass. A four groove barrel would have a 160 passes and would take about 4 hours to complete,,, with a semi automated machine.

A manual machine will be much slower, but since you are not making long barrels and are also not running a production shop it will be more a labor of love and the satisfaction of the craft will be part of the reward. Getting the thing to shoot will be other other part. I have no doubt that it will work, and it will produce better results than a smooth bore. It may even rival a fully rifled barrel.

When I was 11 years old (1961) I got my first issue of Guns and Ammo Magazine. In that issue there was an article on an 8 Bore Evans Double Gun known as a Paradox. Evans made the more "inexpensive" guns more suited to being "working guns" for Africa. This one weighed between 16-18 lbs. These guns were used in the Ivory Trade and were fired literally hundreds of times in a day.( back then Men were really men!!! and ******* didn't show up for a hunt) The reason for the Paradox rifling system was so that the BP wouldn't foul the barrel like it would a fully rifled barrel.

Since I read that article only about 300 times I have retained much of what was said. The gun used Brass cartridge cases with a large charge of Black Powder. The boolits were 1250 gr, cast of pure lead, that's little over 2 3/4 OZ!. They resembled a SWC style boolit with a rounded nose section and one large grease groove which was in the middle of the two driving bands. They also had Round Ball loads for smaller game but the Conical Boolit was preferred form Elephants. We're talkin' serious "Knock Down Power" here!

Only the last 2" of the bores were rifled. thus the moniker "paradox" which was coined earlier by Holland & Holland who produced similar guns in 12 and 8 bore but to a much higher level of finish,,, and price. As did Westley Richards.

The Evans gun used an Underlever which rotated around the trigger guard (sideways) to open and close the barrels and exposed hammers. If I recall it was made in the late 1880's and was the last bastion of Black Powder guns made for Africa before the advent of Smokeless Powders.

The pictures of the sample groups for this gun are indelibly etched in my brain. They were 6 shot groups @ 50 yards being the normal range the gun would have been shot at) 3 from each barrel. There were 3ea. holes touching from the right barrel and about a 3" group 2" high and to the left from the left barrel.

The 1" dia holes in that target are as clear now as when I was 11. even then I knew this was big medicine.

What I have come to realize after 50 years is the size of the "Cajones" the guy who wrote the article must have had in order to shoot that cannon off a rest 6 times in a row!

I have another Cutts Compensator if you want it. I sent the other one to Alaskan Guy. I would have no problem sending one to you in Canada since I ship my Seat Riser kits there all the time with no problem. Nobody would know what it is anyway.

Randy

[longbow]

Randy:

I have made a few minor improvements to the rifling machine mainly because the darn cutter kept coming loose! ! have to think that my woodworking skills are not up to par regarding inletting for the cutter. It worked for the ODG's so why not for me?

So, I decided I would modify the cutting head by epoxying the cutter in place then and slicing off the bottom of the cutter head to make a "shoe".

This eliminates the tiny .2" x .5" paper shims and allows me to use man sized pieces of paper between the shoe and cutter head. More importantly, the cutter can't come loose. It seems like an obvious solution to a problem that my predecessors didn't have. In any case, it certainly seems easier to me. (I am a simple old man)

I will try this all out tomorrow then post photos of my "machine".

Laugh if you will but the the chunk of 3/4" pipe was rifled with the faulty version of this rifling machine and it doesn't look too bad.

All it really takes is to have a reliable pitch to turn that cutter... and some stamina!

Longbow

I really appreciate your post on the old Paradox system. I too have been fascinated for many years by this seemingly simple approach to the "do anything rifle/shotgun".

My intent is to rifle choke tubes to approx. 1:72" and see where that takes me. From an article I have from Ross Seyfried, apparently some Paradox guns ran rather fast twists of 1:36" or so. Much faster than a round ball or "square" slug requires. In any case, I figured that 1:72" was a good start.

Longbow

[MOA]

LB, won't the spin of projectile tighten the choke down so tight it might be very hard to unscrew later?

[longbow]

That is exactly why I am not using a "standard" screw in choke design. The Pachmyr Power-Pac style choke tube has a large shoulder on it. Mine will have a large shoulder to but up on and take the torque.

I have read several posts about standard choke tubes winding is so hard they had to be removed by a gunsmith and some comments about permanent bulges at the threads from torque of the tube.

Also, modern rifled choke tubes tend to run about 1:36" twist where I am running 1:72" so less torque from slower twist too.

Not sure if 1:72" is correct or not as I have read that Paradox guns had slow round ball twists which for 12 ga. run about 1:110" and I have an article by Ross Seyfried that states 1:36" or 1:38" in a gun he has. Since a 12 bore round ball twist runs around 1:110" that should work for a Paradox gun as well since they tended to shoot fairly stubby slugs.

I have read of some heavy slugs as well so maybe some guns were rifled faster for those but they would have to weigh well over 1000 grs. to need 1:36" twist I would think.

Longbow

[nekshot]

Very interesting indeed! You are doing awesome with this endeaver. David Price has a interesting groove design he shows on his website for barrels for his pivot action m\l. I often thought that would work in a shotgun for shot or ball. When I saw your photo I immediatly thought of his barrels.

[nekshot]

got to thinking about fact that paradox guns had the last 2 inches rifled, well whould not a rifled choke tube do or be about the same thing? I have a rifled winchoke laying here for a project and this might motivate me to get it going!

[longbow]

nekshot:

If you have a rifled choke tube you may as well give it a go with slugs. Some people have posted pretty good results using rifled choke tubes. However, there also seem to be some problems with choke tubes torquing so tight a gunsmith has to remove them.

Modern choke tubes are rifled with fast 1:35" or so twist and have shallow rifling. They are intended for sabot slugs to help stabilize and to assist in discarding the sabot.

The choke tube I am planning to make will have wide deep grooves of about 0.010"+ and slow twist of 1:72" which is actually fast for a 12 ga. round ball. 12 ga. round ball wants about 1:110" twist. So, 1:72" should be plenty fast yet not have the rapid angular acceleration/torque of the 1:35" choke tube.

In any case, if you have one try it out and report back. It just may work for you.

I did a little neatening up of the rifling machine and am ready to get back at it to finish the 3/4" pipe test piece. I will take some photos of my machine such as it is. Not fancy but it is working well.

Longbow

[cwheel]

Interesting post indeed. I came by a 3' tube of 4140 DOM tubing for my next muzzle loading cannon project. Tube is 5"OD with a bore of 1 3/8" rough bore. Can picture the finished bore around 1 1/2" after the ream job. Would be fun to try to rifle the next one, see if it shoots more accurately. Can imagine this size could take a few more passes though the bore, still would be fun to try. Those making the rifling machines, be sure and post pics, be interested in cutter forms and the setups, I need to cut 36" long + a little. If I could come by a old Bofors 40mm barrel section, would be better still. In these times, think it's unlikely I'm going to find breach half of a Bofors barrel laying around in good enough condition to use for this, more likely that hunk of 4140 is going to get cut.
Chris

[DougGuy]

My only experience in shooting buckshot through a rifled barrel was a surprise. I use the Mossberg rifled slug barrel with plain old Foster slugs for deer, and it works plenty well, it will cloverleaf a playing card at 100yds which is way more than enough for hunting bambi.

The one round of 00 buck I fired through it was about 20yds from a 4x8 plywood backstop we staple targets on, and for the life of me there was not one single pellet hole to be found on that sheet of plywood. Could it have spun so hard as to throw the shot out sideways far enough to miss a whole sheet of plywood at that distance?

[Faret]

The one round of 00 buck I fired through it was about 20yds from a 4x8 plywood backstop we staple targets on, and for the life of me there was not one single pellet hole to be found on that sheet of plywood. Could it have spun so hard as to throw the shot out sideways far enough to miss a whole sheet of plywood at that distance?
:holysheep

[longbow]

Well, the Paradox guns were supposed to handle birdshot as well as slugs and so they apparently did. Not too sure about buckshot though. Buckshot through a 1:35" twist barrel would be spinning the shot column pretty fast so maybe it opened up that fast. Makes more sense than just the rifling roughing up the buckshot. Make one wonder anyway.

That would be another reason for a screw in choke tube... assuming this all turns out and works. The rifling machine is all back together now an dI did a little more work tonight. I will likely shim another time or two then remove the pipe to see how the rifling is coming. I will take photos when I do that.

Longbow

[uscra112]

Plain iron pipe like that is nasty stuff to machine. Gummy, stringy. No wonder you have problems.

Wonder if you can still get lignum vitae? That would be the wood for your rifling head.

[dave roelle]

http://www.woodfinder.com/search.php?search=Lignum Vitae

Seems its still an option

Dave

[Reg]

uscra112 is actually being very nice in describing plain iron pipe as being "nasty stuff to machine". It's every bit of that and more. For experimental purposes especially in such a short length, think I would get a short chunk of Stressproof . It has some debatable characteristics as far as usefulness goes but it machines like butter and would allow you to perfect your processes. Also better than a piece of pipe would be a short of "Electric Weld" tube or a short of DOM. The Electric Weld has a visible seam in it but it is quickly removed with a reamer. The DOM is basically the same but the seam is removed by internal rolling and I think they run it through some kind of pacification process as it doesn't seem to be as stringy.
Thinking on the rifling head, I have noticed that many of the older heads that I have seen that were made of wood, seemed to be made from a Oak, perhaps a Red Oak, it seems to be very tough.
Since you are dealing with a bigger diameter than say a normal 30 or even 45 caliber barrel it might be such a thing as your head itself be made from some tough wood, red oak or perhaps even lignum vitae ( this to protect the finishing bore ) but say use a 3/8" end mill and mill out a pocket for a tight fittiing piece of square brass and that in turn could be milled out to accept a cutter made from O2. I would try it fitted with a pivot pin at the front and a very ( very ) fine threaded screw in the rear to control the raising of the cutter. I would try to make this elevating screw about 40TPI. 40 TPI = .025 per revolution. Would help control a bit just how much the cutter is raised.
I first saw the process of using the twisted steel , square, rod for a guide in a book on making black powder barrels I got from Brownells many years ago. The author said he made many very good barrels from the process. Yours is the first where someone has ran with the thoughts and am wanting to see how it works out. I think you are on to something.
Please post some pics soon as you can.

[longbow]

Pics coming shortly! I have been too busy on too many projects.

The pipe isn't actually too bad using the file edge cutter. I used the cutter design from the Toad Hall book using the edge of a bastard file instead of a hook cutter.

The wood I used for the rifling head is "mystery wood"... an old hardwood broom handle that appears to be similar to either walnut or mahogany. It happened to be handy, hardwood and about the right size requiring minimal turning.

It was I think a bit soft for the purpose so oak, maple, maybe birch, maybe black locust and a few others would have been a better choice. Lignum vitae might be harder to work than the pipe! Once done it would likely be indestructible though.

However, using the epoxied cutter and large shoe under the cutter, things are going very well. I like that design better than shimming directly under the cutter.

Just don't be expecting fancy when I post pics because fancy it isn't! Functional yes, well finished and fancy, no. I built it out of scrap I had laying around just to get going. If I sat down and designed then made drawings it would be days to weeks of that then trying to procure all the bits. By just building it I have a working rifler that can easily be reproduced and fancied up if a guy wants to.

If I get time tonight I will take some photos.

Longbow

[longbow]

Here they are, the long awaited photos!

Like I said, not fancy but functional.

Here we go:

- photo 1-Assembly: the rifling machine in all its glory (rust and all)
101900

- photo 2-Cutter head:

Mystery hardwood with epoxied file edge in place (inletted into the wood by about 3/8")
101902

- photo 3-Assembly end view:

Showing draw handle, indexing plate with inner bolt circle of 8 and outer bolt circle of 12 so I could do ~ 4 groove, 6 groove, 8 groove or 12 groove. I picked 8 groove for this. I like the idea of deep rifling of at least 0.010", wide grooves and narrow lands. Also shown is my cobbled together pin and clamp to locate the indexing plate to the locator plate behind with clamp studs to hold things together ~ quick release to rotate, locate and clamp all at once. Looks a bit weird but it works really well.
101903

- photo 4-Apart

Here you can see the locator plate on the bolted guide body with two holes in it, one for each bolt circle.
101904

- photo 5-Cutter head

With shims in place as it was used to cut this rifling.
101905

- photo 6-Cutter head parts:

This shoe and large shim approach works very well and is so much easier than trying to handle little tiny cutter size shim papers.
101906

- photo 7-Indexer Plate & Bearing

The indexing plate is a press fit onto 3/4" pipe and the locator plate is a press fit onto 1" pipe (bored to remove seam and fit to 3/4" pipe is pretty good). The bearing is range scrap cast into the 3/4" pipe with the twisted 1/2" square bar centered in place. That worked out perfectly. Quick and easy and perfect fit.
101907

- photo 8-Barrel

Rifling looks not bad! It isn't quite deep enough but I think it proves the point so time to get some 4140 and make a choke tube.
101908

- photo 9-Barrel

Again, rifling looks not bad for a first timer with a crude rifling machine and a piece of pipe for a choke tube simulator.
101909

And before someone else says it... "Hose clamps! What the...!?! Well, crude as it is the hose clamps hold that chunk of pipe just fine. Once I decide on a choke outside diameter (about 1 1/8") I will likely make a choke tube holder that bolts down to the angle trough.

Oh, I should add that I clamp the whole works in my vice when rifling. That sets is at a nice height and works well. That main body tube is a piece of hollow structural steel that used to be my boat trailer tongue until a rather ignorant driver backed into my boat on the trailer and bent the tongue (and cracked the boat glass). "Oooohhh I didn't see that big white and yellow boat" she said... well she said "I didn't see the boat" but it is big and white and yellow.

Choke tube is next on the agenda. I will have to remake my wooden cutter head but no big deal. I may just heat the file edge to soften the epoxy so I can remove it then turn down the cutter head to suit the choke ID of about 0.710".

What would I do different if making another one you ask? Well, I would probably:

- make both the indexer and locator plates a bit larger in diameter
- make the worm somewhat longer by about 4" to 6"
- possibly thread the indexer plate to the 3/4" pipe so I could use it on another worm/bearing assembly. As is, I would have to melt out the bearing or make another indexer plate to put on another worm bearing assembly.
- use more new material and clean rust of old material before taking photos

All in all this one works pretty well so I am happy anyway.

That's all I've got for now. Yeah, I know, I can be long winded.

Longbow

[Reg]

Very good. I like the indexer. Subtend this out to say 48 inches and I can see it doing ML barrels which I is what I am interested in.

I have some good pieces of hedge or Bois d'arc that have been curing for about 2 years. Not quite as hard as lignum vitae but still hard as heck. Should wear well. If you want to try some, let me know.

[AlaskanGuy]

I diddnt see no duck tape on there.... Cant be a home brew without duck tape.... It needs some alaskan band-aide...

:kidding:

[Cap'n Morgan]

Longbow.

I love your choke rifling machine! From the photos the rifling looks more than deep enough. The height of the rifling adds little to the anti-shear force in a contained environment, like a barrel, as the lead has nowhere to go.

BTW: At one time I thought of rifling a shotgun barrel using an expandable multi/micro groove broach, but like most of my whacked out ideas it came to nothing.

[longbow]

I have been thinking about this for a long time but haven't had the motivation until recently. I was originally planning to make the "Traditional Iowa Rifling Bench" per Steve Bookout's manual and video which I have. However, the bench itself is a project and is rather large since it is intended for full length muzzleloading rifle barrels. I really didn't need a major project like that and don't have room for about 9' to 12' of rifling bench in my basement. I just wanted something short to make rifled choke tubes... and cheap and simple. Carving all those grooves in a worm has always made me wonder ~ why not lay strips around the worm then dowel or screw down? Well, some did that but I still wanted simpler and the simplest worm I could think of was twisted square bar.

It happened about 3 weeks ago I was rummaging around my messy shop and found some hot rolled 1/2" square bar (I had been planning on buying some 1/2" keysteel as it is smooth and accurate) but I had this in hand so draw filed the scale off it, clamped one end in the vice with about 14" sticking out, got two large Crescent wrenches on the end like a Tee handle and twisted. Amazingly it came out alright so I got a protractor and twisted to give 1:72" as close as I could gauge. I had a worm!

Next task was to make the bearing. Now I had been planning to use bronze round bar in holders to rub on each flat to guide the worm but my hillbilly buddy in North Carolina suggested casting lead around it and I thought "Why not?" so I did and it worked. The major issues were solved.

From there using what I had on hand and what would fit my little lathe I cut out then turned the locator plate and indexer plate and made a press fit to lightly turned pipe OD's for "press" fit (actually bludgeon fit is more correct since I used a large piece of copper bar to "press" the plates onto the pipe using violent repeated introductions of copper to steel)... but it worked!

I had planned a slightly different locating pin and lock but due to a layout error on my part I had to drill out the pin holes from 1/4" to 5/6" which left little clearance to the 1" pipe (oops!). I started off using a 5/16" bolt through both plate but was fiddling with the nut all the time so went with the clamp "studs" on little arms. That may look funky but again, it is quick and easy to use when rotating the indexing plate and makes for quick disassembly.

The short story is that the twisted worm and cast bearing works well and no reason someone could not use the same idea for a full length rifled.

The cutter I copied from Steve Bookout's manual except I epoxied mine in and shim under which I find easier. The file idea is great! I just used an angle grinder to cut a file up then bench grinder to remove face teeth and set width and length. It may not remove metal as fast as a hook cutter but is easy and works well enough for me.

From there all you need is a bed of some sort to hold the bearing/worm/cutter in line with the barrel and away you go. I used a piece of 1 1/2" x 1 1/2" x 1/8" angle from an old bed frame. The ODG's (and Steve) used wood plank beds then uprights with holes in and wedges to hold the barrel. The worm and cutter was guided on the plank bed.

For quick and easy it is hard to beat angle welded to a chunk of HSS or channel, or whatever, to hold it all in line then use the angle to center the rest.

Hah! I have a rifled piece of pipe now and intend on making a choke tube but have not even test fired my last two or three versions of Brenneke and hollow base slugs. I came to the conclusion that a drag stabilized slug is not likely to provide the consistent longer range accuracy I am looking for. I do like round balls though and the rifled tube should provide good accuracy with them out to 100 yards or so. We will see!

AlaskanGuy: By the time I tried the "Alaskan bandage" it was so oily duct tape wouldn't stick or you would likely see some there.

Reg: Thanks for the offer but I do have other wood that is not "Mystery" wood like I used. With the epoxied cutter the "mystery" wood works well enough anyway. I am more inclined to make a bow out of Osage than a cutter head! I would love a nice bowstave of Osage but I have been too cheap to buy one because I have lots of yew, maple, black locust and a few others. All make good bows but Osage is a beautiful wood especially when made into a bow. I am talking selfbows here not laminated.

I don't see any reason this can't be stretched and full length barrel made with one. If you want to try it out I will be happy to share whatever info I can help with.

Cap'n Morgan: Good to hear from you and thanks. I am not so sure a speeding slug won't strip if rifling is shallow though. I have read some on Fosbery's efforts to get the Paradox system to work and he wound up using deep aggressive ratchet rifling in a choked barrel from something like 0.740" groove to 0.690" bore at the muzzle ~ that is some squeeze down! Possibly the main reason for the spool shaped Kynoch slugs with narrow driving bands and REALLY large, deep groove. In any case, I want at least 0.010" deep rifling with narrow lands just in case.

Longbow

[Hogtamer]

For anybody that has contemplated scratching a bow out of bois d'arc, a piece of steel pipe oughta be childsplay! hehehe

[Reg]

Don't have any chunks of Osage laying around right now that would make up into a bow but should be going back in S.E. Kansas later this spring, will see what I can find.
We just chop it up and use it for smoking. Good stuff !!
Surely it will go through customs ??????? Only other problem might be the length. Have supplied several bowers and they want sections six foot or so long.

[mj2evans]

This is really cool and the reason I hang out on this site .... people actually DO things. I have watched videos on the colonial era rifling process. Really great to see someone actually using this "forgotten" knowledge. Just proves you don't need CNC to make something in metal or a $4k tablesaw to cut wood.

[nekshot]

this is clear as mud to me but i am impressed. This is how I learn, watching and listening. I never heard of that bois arc wood or whatever you call it. Is this stuff harded than rock maple?

[Reg]

I don't think it's harder than rock maple, few woods are, but just the same it is plenty hard enough. Resists decay which is why it is a favored wood for fence posts.
Also called Osage orange, hedge wood. Has a long and very stringy fibrous structure to it, a lot like hickory.



this is clear as mud to me but i am impressed. This is how I learn, watching and listening. I never heard of that bois arc wood or whatever you call it. Is this stuff harded than rock maple?

[longbow]

Osage is tough wood for sure and it makes beautiful bows! Is starts out almost an electric orange colour then gradually darkens to a purpley colour. It is UV sensitive. I guess more importantly it has been a particularly useful wood for bows, fence posts, tool handles and about anything requiring supper tough wood and as mentioned it is decay resistant.

Unfortunately it does not grow where I am. We have something reasonably close but it is actually a transplant ~ black locust. I have made bows form black locust and they do real well. Also an attractive wood and I would say harder than red oak.

I would have figured you were right in the heart of Osage orange country neckshot but maybe I am off a bit.

Longbow

[nekshot]

Longbow you have me at the right place, only that I am here almost 12 years and don't know all goodies about the area. There is a place north west of us called bois de ark or however you spell it! Do you contemplate the ability to rifle a short shot gun tube as from a win 1300 defender or those mossberg shorties?

[FrankG]

Very cool ! Ive read lots on the machines but have never tried to make one . How did you get a good twist on your rod ?

[longbow]

nekshot:

I was planning on making a system like the old Pachmyr Power-Pac using a solder on barrel adapter, muzzle brake then choke tube that has threads near the muzzle and leaving about a 1/2" to 3/4" gap between choke tube and muzzle for gas escape into the brake.

One of the main reasons is so I can have a large shoulder on the choke tube to accommodate the reactive torque from the slug hitting the rifling at full tilt. I have read accounts of rifled choke tubes torquing up so tight they had to be removed be a gunsmith.

The Pachmyr style choke tubes run around 4" long or so. No reason it could not be longer. I do want to try to match "standard" threads though and plan to use a thread pitch of 32 TPI and thread location so that factory tubes will fit... if I can do that.

FrankG:

Mostly by luck!

Funny story ~ I was planning to buy some 1/2" keysteel which is shiny and smooth and accurate dimensions but as luck would have it I found a short piece of 1/2" A36 (hot rolled scaly and ugly steel) in my basement. Being cheap and impatient I decided I would give it a twist to see if it would go okay. First I quickly draw filed the scale off it then got two large Crescent wrenches and put then 180 degrees to each other like a Tee handle, clamped the bar in my vise and twisted. It went pretty easy so I calculated how many degrees twist would make 1:72' twist then used a protractor and eyeball alignment then twisted again. Got it pretty good.

Then when I decided I better cast a bearing I realized I had put a left hand twist in the bar!?! OOPS! That would unscrew choke tubes. So, I reapplied vice and wrenches then twisted the opposite direction, not thinking this would be successful but so it was. Took it back through "zero" then re-twisted the same amount in the opposite direction to get right hand twist. It had a bit of a bow in it so I lined it up along a straight edge then applied arm muscle and vice jaws to take out the bow. Again, it worked well enough.

I drilled and tapped the inner 3/4" pipe at each end for 4 screws to clamp and center the bar, plugged one end of the pipe and poured in some good hot melted range scrap. once cooled things were kinda tight but I squirted some WD40 on the bar then put the works in my vice and wrapped the end of the bar with a mallet. It was tight but moved so more WD40 and a wrap the opposite direction. After a few wraps it was free and moving well so 30 weight oil was applied and I had a smooth running worm in a lead bearing.

Not too difficult at all.

Longbow

[W.R.Buchanan]

Longbow: great job and your rifled piece of pipe looks pretty damn good for a first try. I'm sure you will refine whatever needs it as you progress.

Your idea of using twisted Square stock is the easiest and best way to make a twist mandrel. If you buy Cold Rolled stock it will likely be pretty close to .500 x.500 +/- maybe .001-2, which is close enough for what you are doing. Key stock is cold rolled but it is usually plated with zinc for corrosion protection.

The idea of casting the follower around the mandrel is the way to do that too. If you were to build some kind of jig so that your follower casing (tube) would be held centered up on the mandrel while you poured the lead, it would make it easier to change twist rates since everything would be aligned from mandrel to mandrel. Also the longer the follower, the longer it will last,,, and if oiled frequently it should last a long time since Babbitt bearings in engines do last, and Babbitt is similar to lead.

I think you're on the right track and hope it all works out for you.

Randy

[303Guy]

Very interesting. I just happen to have a single barrel shotgun that is screaming out to fire cast round balls or slugs at feral pigs. That gun was purchased with the idea of suppressing it for possum and rabbit shooting at night in semi-rural areas. Never happened. But an accurate slug gun would be nice.

[longbow]

I am just getting bits together now to make the barrel adapter, muzzle brake and choke tube. I have some old Chevy axles that are just the right size and tough steel. I have read that they are at least 1040 and possibly 4140. Regardless, they are a lot tougher than the barrel I will be putting this onto. I had to anneal the steel and it is still tough.

I have been thinking about using a choked gun in the future and cut the rifling from the muzzle. A modified or possibly even improved cylinder choke should have the right bore diameter and enough wall thickness to rifle if the choke is machined. I have a couple of guns with swaged chokes and I doubt there is enough barrel wall at the muzzle to allow for rifling. My Browning fixed choke barrel has a nice long machined choke and thick barrel walls. It is not a candidate for rifling though!

It might be a bit tricky to rifle and not start cutting the full bore walls though unless the choke is fairly tight to allow deep enough rifling and a bit of a gap to the full bore.

First, I have to machine all the bits then rifle a choke tube to try this.

Again, the goal being something I cannot buy which is deep slow twist rifling suited to round balls and full bore "square" slugs.

I have to turn my cutter head down form 3/4" pipe ID to suit a bore of about 0.700" to maybe 0.710" then reset the cutter. I just need more time! Work gets in the way but I need the paycheck too.

Longbow

[missionary5155]

Greetings Longbow
I am impressed ! This is as good as finding a cool spring out in a hot desert.
How I like to see a plan come together and works well while being simple.
Mike in Peru

[longbow]

Mike:

Well, the rifling machine works but we have as yet to see if I wind up with a Paradox gun equivalent of just a fancy muzzle brake!

I have started turning pieces but it will be a while before I am done.

First projectile down the bore will be a 0.735" round ball. If that works then I will try some conical slugs. If not then we will cross that bridge when we get there.

Longbow

[nekshot]

Just wondering about this and will rifling either a screw in or if you did a whole barrel affect the wad with shot if one was to send a shot load down the tube? I am really enjoying this as I have some shotgun barrels waiting for me to make bp actions for them and it would be neat to shoot a slug or turkey shot load out of same barrel with acceptable accuracy.

[Hogtamer]

nekshot, a rifled barrel will create a "donut hole" pattern with shot - you'll hot everything but the target.

[Reg]

Longbow
Most of the reading that I have done states to rifle the barrel from the breech end rather than the muzzle. Idea being , as things wear you tend to get a taper bored barrel tapering smaller to the muzzle. According to the the great kahuna's this is the hot set up for accuracy. A tapered out barrel tends to spray or scatter things as they come out.
Just a thought.

[longbow]

Yup, that's what I have read too. My take is that the cut "fibers" or "teeth" lay pointing forward when cutting is from breech to muzzle. My Toad Hall book also says to rifle from breech to muzzle but no particular reason given that I have seen. Whatever the reason, I did my pipe test choke that way and had already cut a "forcing cone" in it first. I plan to have a gap of about 1/2" to 3/4" between muzzle and tube based on what I see in the Pachmayr Power-Pac choke/muzzle brake design so need to allow for some lead in to the rifling.

I have started work on the barrel adapter but it is on the back burner for a bit while I make arrows for an upcoming archery shoot. I will get back to it shortly though.

Longbow

[Hogtamer]

Now there's a man with his priorities straight - and his arrows too, no doubt! For someone of your skills kent they must be footed port orford cedar, tapered with hand chopped, shield cut wild turkey feathers and a bone nock! ya'll punch paper or 3-d?

[longbow]

Hogtamer:

You give me too much credit!

I have footed Port Orford cedar arrows with walnut and single fish tale splice but find it a bit time consuming so I came up with a taper drill tool and now use the same taper as for points when I foot arrows. They look good an dshoot well and are much easier and quicker to make... and I am lazy!

For the last several years I have been shooting yellow cedar shafts a friend cut but am running out and he has no more so Port Orford it will be next time.

I self nock and whip... no bone nocks. I do cut my own fletch from full length feathers but not traditional style. I came up with a short high 4 fletch that works very well for me so I have never gone back to 3 fletch. I made my own fletching jigs so I can do 6 arrows at once (one fletch each). Goes pretty quick that way.

We are going to the B.C. provincial traditional shoot on the 3rd weekend in May. it is a great shoot ~ 3D.

Longbow

[longbow]

I am finally back at it and working on my rifled choke tube again! Yeah... I am slow!

I was looking at the drawings and 3D model and it suddenly occurred to me that the way this thing is designed that the tube may oscillate when the slug hits it. The threads are near the muzzle leaving a fairly large overhang behind but even if I moved the threads and made the threaded section longer the tube could still oscillate.

I am looking for feedback on what you guys think.

I am beginning to think there should be a spigot or mating tapers at the downstream end (shotgun muzzle end) to stabilize the tube.

It does have a large shoulder to butt up on but I really don't want to go through the hassle of making this thing to find that the choke tube wobbles enough to affect accuracy. Remember, we are talking thousandths of an inch here.

How do regular screw in choke tubes fit? Do they have a spigot fit at the end? Doesn't really matter for shot but for a slug it may well be an issue.

I have attached a PDF file so you can see the cross section of the assembly. Don't worry about the funky thread fit it is cosmetic. I just didn't start in the same place on the parts.

Also, the gap between the muzzle (barrel adapter on the left) and choke tube on the right is debatable. I have shown it as the Power Pac choke systems show it but I am thinking a 1" jump may be too much especially for slugs in wads. I like the idea of the muzzle brake but the gap could be 1/4" to 1/2" easily and still vent the gas to the brake. The muzzle brake really doesn't have to be there though, it could be a solid sleeve.

I would like to hear what you guys think then assess and change if necessary before I machine it all.

For scale the choke tube is 4" long.

Longbow

[Hogtamer]

Longer threaded section for support? I don't like the jump either, doubt it will do the slug performance or your ears any good. Glad to see you back at it!

[longbow]

Hogtamer:

I am thinking of not going the muzzle brake route and leaving the sleeve solid along with either a spigot for for the back end of the choke tube near the muzzle or using a tapered seat at the barrel adapter so the choke tube seats on that to center it and support it. I am thinking 45 degree or maybe even 60 degree seat so it is solid but not locking.

I was looking at a longer thread but don't like the idea of a long thread because I think it will get gunked up with powder residues and such and be difficult to remove the choke tube ~ too much engagement and friction if dirty.

Yeah... noise... I don't have much hearing left now so I don't need to lose any more. I have read that the Cutts Compensators were rather noisy and I have to think the Power Pacs were as well since so similar.

I'll ponder this a bit more then make a decision and get it built. I am thinking a spigot fit of choke tube to sleeve just past the muzzle is likely the best. That would mean no muzzle brake though which might be a good thing.

Longbow

[RMc]

Perhaps the twist rate of Forsyth Rifling would be of interest.

http://choose-miey.blogspot.com/2011/09/well-its-about-time-again-for-my-annual.html

[longbow]

A good read and matches what I have read about the rifling twist in large bore guns. 12 bore needs about 1:120" twist. I decided to go to 1:72" for lower velocity and use of longer slugs in hollow base. 1:72" maybe a bit quick but way better than 1:36" which seems pretty common now for both fully rifled barrel and rifled choke tubes.

I have read about the Fosbery ratchet rifling for Paradox guns and confilicting reports of twist rate ranging from about 1:38" to slow ball twists of 1:120". Looking at the muzzles of the Paradox gun in the Holland & Holland publication here:

https://issuu.com/hollandandholland/docs/the_shooting_field_15_complete

the rifling twist looks very slow to me. I wonder if H&H would respond to a question? I'll try to find a contact.

Regardless, I decided a relatively slow twist would be better than the current trend of fast twist for sabot slugs. Not sure if 1:72" is too fast or not but will find out because that is what I built my rifling machhine to cut. I can remake the worm and nut but will try the 1:72" unless someone tells me it won't work.

I also like the narrow lands in the Forsyth rifling system. My plan is narrower lands than groove but I wasn't going as narrow as the Forsyth rifling appears to have. I may change that thought.

Slow going but making progress. I did a bit of machining yesterday. One day it will be finished.

Longbow

[RMc]

Paradox guns and ammo reintroduced:

http://www.classicshooting.com/blogs/reading/17662636-definition-of-a-paradox-gun

http://www.classicshooting.com/products/nitro-paradox-ammunition-for-paradox-guns?variant=1179491392

[Ballistics in Scotland]

I've only just seen this fascinating thread. First, very shallow rifling indeed is fine for a muzzle-loader with lead-to-bore contact. Metford found that scratches made with coarse emery on a lead lap would work until they eroded smooth, and it doesn't have to be very deep to resist black powder erosion. What is different in your situation is the bullet meeting the choke when it is practically at full speed, and having to take the rifling then. That is why Fosbery found deep rifling to be necessary. There is nothing very original about either the twist of the Forsyth rifling, and the narrowness of the lands is just an extreme example of what was common practice. If you try for narrow lands it would be a good idea to have an odd number, since one directly opposite the cutter would reduce the tendency to chatter. Extremely narrow lands are also very easy to wear with a cleaning rod or ramrod, so a protecting bush on the rod would be useful.

There are rifled choke tubes available, but some are made to spread small shot for hunting in close cover, and it is possible that some of those might be more deeply rifled than you would want with a solid ball or slug. Normally the choke tube can't act as the kind of bore obstruction which causes a bulge. But a long extended one might. Here is an example of a double ring-bulge I provoked experimentally in a derelict single shotgun. The first bulge is produced by the pressure of gas, which is very elastic, piling up behind the obstruction. So unless the obstruction is totally immovable, the bulge will occur something in the region of an inch further along the bore. The second bulge is produced by that gas cushion bouncing back, bouncing again from the breech face, and coming back to hit the obstruction for a second time. It happened in less distance than the length of an extended choke tube.

Incidentally the use of shot in a rifled bore or tube shouldn't make much of a doughnut pattern if everything else is well. The shot is widened by centrifugal force, but the shot near the centre are describing a spiral of much smaller diameter, so their outward movement will be less. What may happen is that if the outlying layer of shot are deformed by the rifling, they may fly wide of the rest of the pattern. But that has been made less of a problem than it used to be, by the use of shot-cup wads.

Twisting a square metal rod to make your rifling guide rod could work well, but it needs to be good quality metal and closely dimensioned if the spiral is to be totally consistent. You can't do it hot with any sort of equipment the amateur is likely to have, for the same reason. A gain twist is mildly beneficial if done well, but people warn against rifling which accelerates and then decelerates, or vice versa. I don't know why they should be very different, but they may be.

179119


One possibility would be to cast an alloy plug around the rifling rod in an existing rifled barrel. For a good bullet muzzle-loader a 12ga Hastings barrel would be ideal, and you could even do it without damaging the barrel of an existing gun. You could use this setup either directly or to cut a groove in a guide cylinder. Do it with a ball burr or ball nose end mill in a metal cylinder, and you could solder a matching round wire into it.

Forty passes per groove sounds about right, and they don't make paper shims that thin, although they are find for spill boring a smooth bore. I think you need the usual arrangement of a square or rectangular bit sliding in an inclined trough, held by a spring at one end and an adjusting screw at the other. I'd prefer a brass or bronze cutter holder, which if necessary you could make up by silver soldering pieces of metal together and turning the resulting block round. Any very hard wood should do, or a laminated phenolic plastic such as micarta or tufnol. In this case I would line the bottom of the slot with metal.

[longbow]

BIS:

Good to hear from you.

I have already built my somewhat crude but effective rifling machine. I cold twisted a piece of 1/2" square bar to as close to 1:72" as I could determine. It is polished smooth then I cast wheelweight lead around it so perfect fit. I had a heck of a time getting it to move at first so whacked it with a mallet then sprayed with WD40, repeat until it moved, more WD40 and eventually I have a nice slide fit with no slop.

I made a wooden rifling head using a piece of file for a cutter and proceeded to rifled a piece of 3/4" pipe which came out very well. It was work but it worked.

I do not plan on using extremely narrow lands, probably about 1/2 the wide of grooves of maybe a little wider.

I like deep because as you say that slug is ripping along when it meets the rifling. Fosbery used ratchet rifling I think to maximize "traction" on the driving face and minimize slug distortion. I woulc like to know the typical twist rates though. My understanding was that bore guns used slow round twists for round ball and "square" slugs but IIRC the Ross Seyfreid article mentioned 1:36" twist for his Paradox gun. In any case, I have been told both slow and fast. I have to think that if there is no skidding then slow is best for round ball or square slug.

I have seen the use of an existing barrel to make a rifling guide then use that for rifling a new barrel to same twist but I do not have anything rifled to 1:72" or slower. The closest I have is my old CVA Hawken kit rifle with no-removable breech plug so a no go and it is 1:66" so even a bit faster.

For a short rifled choke tube the twisted bar works just fine and is easy. I was planning to build a rifling bench on the Seabolt pattern and bought the Toad Hall book:

http://toadhallrifleshop.com/rifling-worms-video/

but that is a project on its own and requires significant room just to store the rifling bench. I already have a bowyer's bench I built and it sits on pour back porch now. I really don't need any more "furniture" that only hold one person and not so comfortably! If I was making a full length barrel i would either use an existing barrel or make a rifling bench but my small machine works for this.

Actually the shimming worked very well, I used parchment paper that is about 0.0015" thick but due to compression it worked quite well. I ran through each groove until there was little resistance then indexed and repeated for each groove. I plan to do the same for the choke tube with the addition of indexing through each groove with the finishing shim pack to make all grooves the same.

I agree that a sliding cutter on an inclined face would be much better and if I were to go into production I would get much more sophisticated with my rifling machine and head than I have for this little project. I figure if Bookie can make a wooden worm and rifle a full length barrel accurately my twisted bar should do as well. The ODG's did it too and made some fine weapons.

I am just rethinking the choke tube and muzzlebrake after looking at the overhang and may change things some. I will likely rough turn a piece of round bar for a choke tube though then bore and rifled it without working the outside just yet. If the rifling turns out well then I can change thread length or location later then finish the choke tube later and make muzzle brake/sleeve to suit. I want a rifled tube before I do all the rest of the work.

Longbow

[longbow]

BIS:

It occurs to me that you live in the land of Paradox guns and bore guns. Do you have access to any? I am really curious about twist rates especially for the Paradox guns.

If you could get that info I would be forever in your debt.

Longbow

[Cap'n Morgan]

Longbow,
I would skip the muzzlebrake holes (little, or no effect in a shotgun) and extend the choke-extension for a tight fit over the barrel for at least 1.5" This would give you a good barrel/choke alignment even if the choke should work loose. Make sure you have at least .01 freebore/taper in the choke - perhaps even a smooth section to guide the slug before it meets the rifling.

[longbow]

Cap'n Morgan:

Good to hear from you! It has been a while.

I have changed the choke tube and muzzle brake a bit to move threads to the mid point, shorten the muzzle brake and reduce clearance gap to .375". Otherwise same choke tube of 4".

Yes, others have commented on the noise from the muzzle brake being objectionable.

I will likely leave some holes in the muzzle brake/sleeve simply to keep crud from building up. I had a Pacmayr Power Pac many, many years ago but no muzzle brake so I made one and installed it. It looked much like my new MK I muzzle brake. Actually it was not that noisy but maybe because hole area was smaller than stock? Anyway it looked good and when shooting BP loads was pretty spectacular with the muzzle flash. I was playing with BP and 0.690" ball loads back then.

I may start with no holes to see how it goes then possibly add some to see how that works or what effect it has. I can always make another sleeve.

The choke tube design is 4" long and has a gentle tapered lead in from beyond groove diameter to bore diameter over 0.75" so the slug will get a nice tapered lead in. I may add a short groove diameter smooth section too or maybe a steeper taper then a short groove diameter smooth section more like a chamber throat. I am undecided as yet and looking for opinions so thanks for that.

I hadn't thought of a spigot fit to barrel. Not a bad idea. I'll ponder that some and maybe model something up. It would likely be easier to thread the outside of the barrel and screw the tube onto that eliminating barrel adapter and sleeve. I would still be able to make the choke tube heavy duty unlike the thin internal choke tubes. I have no way of threading the barrel though so would have to get someone with a larger lathe to do that.

Alignment is one of my concerns with so many pieces. On that line I could eliminate the sleeve and screw the choke tube directly onto the barrel adapter making it all external. With some barrel extending past the barrel adapter I would get the spigot fit and less pieces.

Hmmmmm... that is certainly worth taking a look at.

Lots of things to think about.

Thanks for the input.

How is your Brenneke project going? It seemed like you were making good progress last post but I haven't seen anything for a while. My preference is still an accurate smoothbore slug and you were well on your way there.

Longbow

[Col4570]

I have rifled barrels in the past,a good rifling bar can be made from 3/16th" x 1" mild steel bar twisted and run between two rollers.For the rifling head a cutter must have no top rake but the end rake should be the radious of your grindstone,exactly as you would when sharpening a lathe tool.My rifling heads are Steel with an adjusting screw that pushes a wedge that adjusts the height of the cutter.My last Rifling I used my whitworth rifle Barrel (one turn in Twenty inches),as follows,Make a rod with the rifling head at on end,Make some saw cuts at the other end,Fit a wad in the barrel,Stand the barrel and rod upright,heat the barrel until water sizzles on it (Spit),pour in molten Hard Lead.Using plenty of oil pull and psh iside the new smooth bored Barrel until it stops cutting then index round one whitworth flat and repeat until all grooves are cut.pull the cutter out and adjust 1/4 turn of the screw and repeat the cutting sequence until the required depth.

[Ballistics in Scotland]

BIS:

It occurs to me that you live in the land of Paradox guns and bore guns. Do you have access to any? I am really curious about twist rates especially for the Paradox guns.

If you could get that info I would be forever in your debt.

Longbow

I don't have access to any, and they are quite uncommon nowadays. They would be subject to the same licensing as rifles, rather than the type for shotguns - for a along time none whatever, and even now relatively easy to get. Add the fact that they have very little use for anything in the UK, and I would suspect that many were bored out as ordinary shotguns, just as many rook rifles unfortunately were.

You have to remember that "Paradox" was a Holland and Holland trademark for the guns they made under Col. Fosbery's patent of1885. It was much copied minus the name - possibly early on, for I don't know how much of it was protected by the patent, and certainly for a brief period after the patent expired. Names like "Jungle gun" were often used, and I wouldn't put it past the Belgians to find the odd Panados or Paradoz on Skid Row to rent out his name for what were, usually, firearms of quite reasonable quality. All of these were very much the gun of the casual hunter - farmers, travellers, even missionaries - and their period of real popularity wasn't long. Smokeless powder and jacketed bullets were almost contemporary with the Fosbery patent, and events forced millions into intimate acquaintance with the bolt-action rifles which became very cheap on the surplus market.

WW Greener writes that the original Paradox had a "sharp spiral", which 36in. would be for the types of projectile intended, and says the shot pattern was better than a cylinder bore. The latter claim surely means tighter, and might not be greatly significant to many users, but it encourages me to believe Wikipedia when they say only the last two inches were rifled. If the diameter of a choke extends further than that, it will no longer tighten the pattern, as the inward movement of shot, which accomplishes this, will have ceased.

In a lead-bullet rifle there is usually some slight slippage in the rifling as the bullet starts moving, but for most of its path the rotation closely matches that of the rifling. This is not necessarily the case when it hits the rifling at speed. It is possible that the "sharp" spiral is the one that Col. Fosbery found would impart the minimum rotation a ball or short bullet needed.

Under other circumstances loosening of the bullet in the rifling is considered a receipe for disaster. But in this case loosening at the front and rear of the grooves would be accompanied by diametric tightening up, so the bullet shouldn't go off-centre. It is also possible that gas leakage can spray atomised lead ahead of the bullet, to be ironed into the bore as it catches up. But ironed into where, if it begins in the last two inches?

I have somewhere an old magazine heralding the debut of an odd new device known as the Thompson-Center Contender, adaptable from .45LC to .410 shot. I don't know if there is any legal way to market a smoothbore cartridge pistol in the US, but there certainly isn't a commercially attractive one. So they did just the opposite of what you envisage, by producing a rifled pistol with a screw-on straightening-out tube for the shot. If I remember rightly they are vented to prevent a pressure wave as a bore obstruction, as they might otherwise would with shot, and surely would if some member of the intellectual classes fired a bullet through it.

[longbow]

Yup! I have seen those TC Contenders... in magazines only. It seems to me that they were illegal in Canada due to interchangeable barrels but I wouldn't swear to it. I've never seen one in person in any case.

The .45/.410 seemed like a good idea to me though I suspect it would appeal to a small niche group. I have read of people trap shooting with them though not at usual trap ranges.

Yes, Fosbery the ratchet rifling system though I am not sure of the benefit of it. There was a largish edge on the the thrust face of the lands with the top of the land sloped back down to the following groove. I have read that the rifling was quit deep so possibly the wedge shaped land resulted in a large thrust face but minimal distortion of the slug where flat top lands would displace more lead.

I have also read that the Paradox rifling was choked down to as tight as 0.690" from bore diameter of 0.740". I am not sure if the choke applies to both lands and grooves or lands only... which would be the result if you rifled straight through a choke. I think it would be difficult to produce choked grooves by cutting.

All in all it would be more to my liking to get an acceptably accurate smoothbore slug to work but so far I have been unsuccessful in reaching my acceptable level of accuracy to 100 yards with smoothbore slugs. I am hoping Cap'n Morgan succeeds as he well on his way with a Brenneke like clone.

In fact if I can find some Brenneke slugs or loaded ammunition I will retest as I have not shot any genuine Brennekes for about 30 years. No access where I am now.

I will also order some Thug slugs from BPI to try those out. Even if they work, it is difficult for the home tinkerer to reproduce a slug like that. Well, not the slug but the attached wad.

I did try Gualandi DGS slugs a few years ago and was not too impressed. I had some keyholes at 50 yards and recovered slugs showed that the plastic wads had rammed into the lead skirts causing distortion. Overall they didn't shoot badly, just not well enough.

The quest conitnues!

Thats for the replies so far. Keep 'em coming!

Longbow

[W.R.Buchanan]

Long Bow: What you have pictured should work just fine. I don't see any oscillation potential. Just make sure your forcing cone is all the way out to the OD of the choke tube.

That way there's no chance the slug or the debris will get shaved off during the transition.

As far as the twist rate? since you are making the tubes you can try many different rates and figure out what works best. I would point out that the really slow twists were for Patched Round Balls.

A cylindrical projectile must spin at some speed in order to remain stabilized. I think that rotation speed is a function of Length and Diameter. and if you searched around you could probably find that formula. I bet if you called Berger Bullets and told them what you are trying to do they would tell you what needs to happen.

I think at the velocities you are going to see with shotgun cartridges something more like 1:20 might be in order.

Compare the length and diameter of a .45-70 slug with your slugs. and if the proportions are similar, use that twist rate.

Randy

[longbow]

Randy:

I understand the issue with patched round balls. That is why I want slow twist. Round balls do not require a fast twist nor do "square" slugs (as long and they are in diameter). A 12 ga. ball wants about 1:120" twist so very slow. I decided to go with 1:72 as a bit of a compromise. It is fast for a ball but still slow enough that I can envision the slug picking up that spin when ramming into the rifling at say 1200 to 1500 FPS. If I am wrong and there is skidding then the 1:72" twist should still impart enough spin to make the ball accurate. That's my story and I am sticking to it... for now anyway.

I have read posts about the modern rifled choke tubes providing amazingly good accuracy but the current posters here are not confirming that nor have I seen any confirmations on other sites... or targets with cloverleafs. I suspect if it were true or even close there would not be so many fully rifled guns out there.

The Paradox guns had a very short (3" or so) aggressive rifling of some twist I believe between 1:36" and 1:120" or so in 12 ga. I want to shoot round balls or at least slugs that don't weight 800 to 1000 grs. so a slow twist is in order... I think anyway.

My understanding is that the bore guns shooting round balls used very slow twists as did the patched round ball guns.

I believe the fast twists we see today are due to the sabot slug trend. Many sabot slugs are relatively long for their diameter so require a relatively fast twist to stabilize.

I may be wrong here but I am hoping I am right. If I get this thing built and mounted correctly then only the rifling twist should be the determining factor. For mounting I plan to make a mandrel that fits the bore of the shotgun barrel and the bore of the choke tube to ensure that when the barrel adapter is silver soldered to the barrel that the choke tube is dead in line.

If I do not get decent accuracy then I will make another choke tube with faster twist and try that. If that fails well... I'm not sure but let's think positive here. I still like the versatility of the smoothbore for whatever reason, that's just me, so I'd prefer an accurate smoothbore slug which I have failed at producing (to my standard at 100 yards anyway). The next best is a removable rifled choke tube that can be replaced with a conventional choke tube for shot.

Having said that I did get some pretty darn good accuracy with 0.735" round balls shot in a borrowed Remington 870 with rifled barrel at 1:36" twist. However, it is one thing to start a ball out in a "fast" twist and another to have it meet that fast twist when it is scooting along at 1400/1500 FPS.

Anyway, we'll see shortly I hope.

Longbow

[Ballistics in Scotland]

The Hastings barrels by Verney Carron are worth looking at. As you have found, a fully rifled barrel can work well, and I doubt if it would throw an unacceptable shot pattern for small game in close cover. But rather than rifle a choke, it would be possible to ream a rifled barrel smooth for most of its length. If I remember rightly the Hastings barrels have a .716 land diameter. Hand reamers usually have a tapered lead of about 1/64in. taper, so a reamer of 18.5mm., the international standard for a 12ga. bore, should remove the rifling and give a suitable transition.

http://www.hastingsbarrels.com/

On the matter of screw-in choke tubes jamming, I think it is a possibility. Or they might come with left-hand rifling, which tends to unscrew them. The possibility of the tube heading for the horizon isn't a great one if you fire only a few shots and check it, as it can turn only a fraction of a turn at a time. Bearing on a shoulder outside the barrel might be the best plan, like Winchokes. Those are supplied with a C-wrench to turn them by one of the circumferential holes. But a stronger grip would be obtained with a circular wrench, and screws engaging with several holes.

We aren't allowed to post eBay auction URLs, which is the fastest way of getting an illustration. But if you do a search there for dog set screw or dog grub screw you will find some which would be very suitable. It would also be possible to have a concealed choke tube bearing on nothing but the threads, and prevented from rotating by a set screw through a front sight ramp. There should be no way that one could jam.

[Cap'n Morgan]

How is your Brenneke project going? It seemed like you were making good progress last post but I haven't seen anything for a while. My preference is still an accurate smoothbore slug and you were well on your way there.

Longbow

I pretty much finished the "original" Brenneke project as I felt I had achieved my aim of a decent group from a smoothbore at a hundred yards.

http://i1370.photobucket.com/albums/ag248/driftwood4/b4838f43-92b7-4274-adf5-c7cde8e28bc5_zpsdq97ecau.jpg (http://s1370.photobucket.com/user/driftwood4/media/b4838f43-92b7-4274-adf5-c7cde8e28bc5_zpsdq97ecau.jpg.html)

http://i1370.photobucket.com/albums/ag248/driftwood4/b22743d9-d3b0-46b6-be39-91172dbe4a3a_zpsrupzbxct.jpg (http://s1370.photobucket.com/user/driftwood4/media/b22743d9-d3b0-46b6-be39-91172dbe4a3a_zpsrupzbxct.jpg.html)

I'm still planning on some new nose designs on the Sleeve-Slug. One of the things I've learned the hard way over the last few years is, that the nose profile can make or brake the way a slug behaves: My first design had a nose resembling a 45 long colt, and it gave pretty good accuracy. The next design had a huge meplat - almost like a wad cutter - and while quite accurate at shorter ranges it would start tumbling after fifty yards. The last design - the "Propeller-head" - which was meant to cause a slight spin in the slug - was a hopeless disaster with the slugs dispersing all over the target.

At the moment I'm working on a buckshot #4B wad design which may, or may not (probably not), be the holy grail for a tight buckshot pattern. Time will tell... ;-)

[Ballistics in Scotland]

Were those groups with both barrels, or only one? They still turn the shotgun into an extremely useful deerhunting weapon in situations which are all some hunters encounter. Was there any choke in the gun? It has always been part of the problem to find a way of getting good slug accuracy from the same muzzle as gives a moderately close shot pattern.

I am not surprised at the failure of aerodynamically spun slugs. That is the sort of thing that is just about excusable for the experimenter in an amateur capacity, but anybody selling the things should know better. As for the large meplat, here is a picture I have posted elsewhere. It shows how a tilting round-nosed bullet increases the drag on the side it is tilting from, producing some tendency to right itself, but a large hollow in the point increases drag on the side it is tilting towards, so over it goes. An almost totally flat nose would be at best part-way between the two.

179290

A device sometimes used in slow-twist rifle bullets was large lube grooves, vertically sided at the rear but sloping at the front. The theory (and with rifling it is hard to tell if it is totally untrue) is that it would impose straightening drag on a tilting bullet.

[longbow]

Cap'n Morgan:

Looking very good indeed! Congratulations! I know I would be happy with that group. I don't recall seeing that posted before and I try to read all you posts.

Is that group from the full bore Brenneke or the sleeve slug? Full bore Brenneke I am thinking but either way, excellent work!

I am with you on nose shape. I don't like really large meplats and my designs are mostly a moderate meplat TC. My favourite design is the Kynoch style slugs for Paradox guns. The only thing I don't like about them is weight. They are a bit heavy to go out and "plink" with but I think they would be perfect for hunting or bear defense.

Not sure how they would do if made into a hollow base design to lighten them some. Might be worth looking into.

My second favourite is the old Dixie Tusker at 600 grs. It has a nice meplat and TC nose. I am actually surprised that no-one with a rifled gun is reporting use of this nice design. I saved the drawing when James posted it and would get a mould made if I had a rifled gun.

turbo1889 posted that the Lyman 525 gr. sabot slug had too large a meplat to remain stable if shot from a smoothbore gun at supersonic velocity. He claimed that they tended become unstable at transonic velocity. I have never tested those slugs so no personal experience but turbo knows his stuff. If anyone has tested them at various ranges from a smoothbore. I'd be interested in results.

BIS:

Now there is a novel idea of reaming the rifling out of a fully rifled barrel. I hadn't thought about that one but being cheap (I like to think "frugal") I doubt I could bring myself to do that to a nice barrel. I'd rather just order a fully rifled barrel for my BPS or get a fully rifled gun.

Also, that would leave the rifled portion with shallow fast twist rifling where currently my goal is deep slow twist rifling. Not saying the fast twist won't work but it would be basically the same as a modern rifled choke tube.

Now having said that, a guy smarter than myself might have started with a modern rifled choke tube and altered from there if necessary and I probably should have gone that route using standard modern choke tube in a tapped barrel. Then if it didn't work I could have bought a blank choke tube and rifled with my machine to get the rifling I want. However, I don't have a gun with tapped barrel so decided to add on per the Cutts Compensator/Power Pac method.

I am starting to think I should have picked that route but I figured by the time I got the barrel tapped and bought a choke tube or two I could make what I want. We'll see I guess.

As for the jamming bit, that was one of my main concerns as I have read that some choke tubes do jam up very badly due to torque. However, I have not done any real research here and it may vary by choke tube design. Some seem to butt solidly on the muzzle so that should be okay. And you are right, I am sure there is a method to stop the tube from jamming so again maybe I should have gone that route. But here I am at this point so I'll carry on but maybe with some changes.

I kinda have the vision of the Paradox like muzzle stuck in my head so that is the route I have been following. That and so far I have not read very many positive things about performance from modern rifled choke tubes.

And I am stubborn. Who else would take this long to try to get decent accuracy form a smoothbore with slugs he can make himself? Well, Cap'n Morgan but the has the ability to make a commercial grade slug... or maybe better than commercial grade as they are impressive to say the least.

Here I go rambling on again. I'll be back working on this thing again later.

Longbow

[Cap'n Morgan]

Bis,
Both groups are shot from the bottom barrel (true cylinder) As I recall it the top barrel will actually print a little higher - even if the tapered layout of the barrels would suggest the lower barrel to shoot higher. No doubt the muzzle jump from recoil plays a part here.

Longbow,
The full bore Brenneke clone was used for those groups. The sleeve slug is less accurate, but not all that much, about 4" at fifty yards, where the clone will do 3" or less. So far, I have not tried the sleeve slug at ranges over fifty meters, except for the large meplat slug which started to tumble beyond that range. Since the large meplat slug mold had been re-cut from the original mold, I had to make a new mold with the original nose profile. Extra work I know, but you win some and you you lose some... I still hope to improve on the sleeve slug by tinkering with the nose profile.

[Ballistics in Scotland]

Bis,
Both groups are shot from the bottom barrel (true cylinder) As I recall it the top barrel will actually print a little higher - even if the tapered layout of the barrels would suggest the lower barrel to shoot higher. No doubt the muzzle jump from recoil plays a part here.

Longbow,
The full bore Brenneke clone was used for those groups. The sleeve slug is less accurate, but not all that much, about 4" at fifty yards, where the clone will do 3" or less. So far, I have not tried the sleeve slug at ranges over fifty meters, except for the large meplat slug which started to tumble beyond that range. Since the large meplat slug mold had been re-cut from the original mold, I had to make a new mold with the original nose profile. Extra work I know, but you win some and you you lose some... I still hope to improve on the sleeve slug by tinkering with the nose profile.

That is about what I thought. To get groups like that would be amazing if it were with both barrels, and choke. It should be possible to bring the two barrels closer together by using a lighter, faster slug. Adjusting powder alone, even if it comes within the limits of safety, is unlikely to make much difference.

If the choke tube tightens up on a flange overlapping the muzzle, you could put a thin plastic shim washer in there. I don't believe the muzzle will get hot enough to melt it, with the sort of shooting you normally do with slugs. But you could easily loosen everything up by heating the muzzle with one of those little piezo-igniting torches you fill from a lighter gas canister.

[longbow]

Another good point. I suspect that if the choke tube has a shoulder that butts against the muzzle it should not lock up too tight to remove and even if it got a bit stubborn the heating as you say should work well.

I was just cutting metal to turn for parts and am really thinking I should ha used a commercial choke tube system then just bought a blank choke tube for rifling.

Oh well, I'll get some use out of my old lathe this way.

Hah! Not to mention the fact that I am envious of Cap'n Morgan's success with his Brennekes so am thinking of revisiting my mould and making a change or two then retest those.

Too much to do and not enough time... or money!

Longbow

[Ballistics in Scotland]

There used to be (maybe still are) choke tubes intended to be permanently soft soldered into a rebated muzzle. They would be virtually invisible. Unfortunately buying a Hastings barrel just for one or two three-inch chunks isn't very frugal.

I started thinking of a tube bearing on the threads alone, with a screw in a front sight ramp preventing it from unscrewing. But with a double, of which one barrel would still be used with shot only, there is a better and easier way. That would be to cut a half-moon notch into one side of the flange, into which the unnotched smoothbore tube interlocks and stops it from turning.

You will seldom find a Paradox carried by the heroes of romance. But I can't resist posting a story in which there figures "a double-barrelled gun that could be used either for ball or shot", with cartridges with brass cases to protect them from the damp. Rider Haggard generally knew his firearms:

http://www.gutenberg.org/files/2857/2857-h/2857-h.htm

[victorfox]

Congrats brother. I wish i had the skills to do such things. I'm struggling to build a simple underhammer. My mechanic skills suck badly.. ...

[Ballistics in Scotland]

Congrats brother. I wish i had the skills to do such things. I'm struggling to build a simple underhammer. My mechanic skills suck badly.. ...

They'll be better when you finish than when you started.

[longbow]

Well, I used the "Contact" on the Holland & Holland website to ask what the rifling twist was and the gun room manager just emailed me with a response. The H&H Paradox guns use 1:30" twist which is very fast.

The Kynoch style bullet loaded fro those guns want about 1; 63" to 1:86" twist depending on what formula is used but in any case, much slower than 1:30". Not sure if they count on skidding of the boolit so not picking up the full twist rate but at 1060 FPS it shouldn't be too hard to spin that boolit when it hits the rifling.

I have now asked him why such a quick twist. No sure just how many questions he will answer but hopefully this one more. I was actually a bit surprised I got a response.

Looking through the website I have to say that they certainly make beautiful guns. I will never own one but I can window shop. If I ever win a lottery I know where at least some of the money will be going!

Longbow

[W.R.Buchanan]

LB check out this guys rifles. He makes really nice Underhammer Muzzleloaders in calibers all the way up to 12 bore. There is some info on the twist rates, and types of rifling used as well, and the whole site has a lot of info that might translate to your project, as well as some nice pics of some pretty decent custom work.

Well worth a look.

Hope it helps some. Randy

http://pacificriflecompany.blogspot.com/2010/06/welcome-to-pacific-rifle-company.html#links



http://rjrenner.blogspot.com/

[longbow]

Thanks Randy. I have seen the Pacific Rifle site before.

Another is October Country:

http://www.octobercountry.com/oc-sporting-rifles-62-66-69-72-and-75-cal/

They both run 1:104" twists for .72 cal.

At one point I contacted one or maybe both companies about supplying me a chunk of barrel to make a choke tube out of. I was declined. I can't recall the reason but that's why I decided to make my own little rifling machine.

I am set up for 1:72" twist and at this point that is what I will use unless someone can convince me it is a bad idea.

I know the big 'ol round ball guns use very slow twists and those work for round ball and that at least some of the bore guns were rifled with very slow twists for round balls or square slugs so I am a bit surprised to hear that H&H uses 1:30" twist in the Paradox guns and the rifling does not appear to be ratchet rifling. From what I see on their website the rifling looks conventional.

In any case, I know that a 0.735" round ball will stabilize in a:35" or 1:36" twist (Remington 870), that 12 ga. round balls stabilize in 1:104" twist and that the bore guns also used slow twists for balls and bullets. So, I am thinking 1:72" is fast enough and not too fast for what I want. If I am wrong, I guess I am wrong but will start with that and see what happens.

I am a bit surprised that H&H uses, and likely used in the past, such a fast twist. Not sure why as the boolit sure doesn't need that fast a twist and I can't think that it is to impart enough twist because of skidding because that could be unpredictable unless absolutely everything was identical. I have to think the boolit is spinning at 1:30" as it leaves the muzzle or lead would be shaved.

Anyway, I will try with my deep slow twist rifling and see where it gets me.

I would still rather reach my goal using a hollow base or Brenneke style slug from a smoothbore. So far that has eluded me so I will try this. I am hoping to test some more slugs next weekend so we'll see how they do first but I will likely build this rifled choke tube to try regardless of future smoothbore test results unless they are spectacularly good which is unlikely.

Longbow

[longbow]

Well, I have to say that I am impressed!

I have contacted Holland & Holland twice now and have received two responses to my questions from the London gun room manager. First was to ask the rifling twist and the second was in response to a question as to rifling form which appeared to be conventional rifling in a photo I found in a link on the H&H site ay Classic Shooting Co.

The gun room manager sent me the Fosbery patent drawings which I already have and a couple of photos which clearly show the rifling being a ratchet style rifling (though not exactly like the patent drawing) which he said was Baker rifling.

He did not have a definitive answer as to why the rifling twist was so fast for the Paradox boolit which should stabilize in no faster twist than about 1:60", simply that they had measured several original Paradox guns to determine that 1:30" was the twist originally used.

I am very impressed that someone in his position would take the time to respond to my questions and to respond quickly as well.

Should I ever win a lottery and desire a fine gun (who wouldn't!?!) H&H would be my first stop and a side by 12 bore Paradox gun first on my list.

I doubt I will ever be able to afford an H&H Paradox gun or for that matter any of their fine guns as prices for used guns seem to start at tens of thousands of dollars and range up to hundreds of thousands of dollars.

There are some other makes that are only a few thousand dollars used so maybe one day...

Back to rifling...

There is a photo of a Westley Richards Paradox gun in the NRA museum that appears to have rifling exactly as per the Fosbery patent drawings:

http://firearmshistory.blogspot.ca/2013/12/is-it-shotgun-or-rifle-paradox-gun.html

http://www.nramuseum.org/guns/the-galleries/theodore-roosevelt-and-elegant-arms-1880s-to-1920s/case-28-an-age-of-elegance/westley-richards-super-magnum-paradox-side-by-side-shotgun.aspx

The photo of the H&H Paradox muzzles looks more like conventional rifling with a ramp on the trailing side of the rifling rather than the ratchet style Fosbery patented:

http://www.classicshooting.com/blogs/reading/17662636-definition-of-a-paradox-gun

Longbow

[W.R.Buchanan]

LB: I made a trip to the SCI Show in Vegas last year and was amazed at the prices of used English guns.

The one in the pic below was "On Sale" at $160K marked down from $199,995! it was a Westley Richards double rifle in .450 NE and I only took a pic of the buttstock as the wood was something I had never seen before.

There were plenty more in that price range at that show.

$10 grand wouldn't even get you an Enfield Sporter made by one of the big houses! They are pretty proud of their stuff, but the work is also pretty much second to none.

These outfits invented the good stuff! And they aren't ashamed of it at all.

Randy

[Ballistics in Scotland]

Well, I have to say that I am impressed!

I have contacted Holland & Holland twice now and have received two responses to my questions from the London gun room manager. First was to ask the rifling twist and the second was in response to a question as to rifling form which appeared to be conventional rifling in a photo I found in a link on the H&H site ay Classic Shooting Co.

The gun room manager sent me the Fosbery patent drawings which I already have and a couple of photos which clearly show the rifling being a ratchet style rifling (though not exactly like the patent drawing) which he said was Baker rifling.

He did not have a definitive answer as to why the rifling twist was so fast for the Paradox boolit which should stabilize in no faster twist than about 1:60", simply that they had measured several original Paradox guns to determine that 1:30" was the twist originally used.

I am very impressed that someone in his position would take the time to respond to my questions and to respond quickly as well.

Should I ever win a lottery and desire a fine gun (who wouldn't!?!) H&H would be my first stop and a side by 12 bore Paradox gun first on my list.

I doubt I will ever be able to afford an H&H Paradox gun or for that matter any of their fine guns as prices for used guns seem to start at tens of thousands of dollars and range up to hundreds of thousands of dollars.

There are some other makes that are only a few thousand dollars used so maybe one day...

Back to rifling...

There is a photo of a Westley Richards Paradox gun in the NRA museum that appears to have rifling exactly as per the Fosbery patent drawings:

http://firearmshistory.blogspot.ca/2013/12/is-it-shotgun-or-rifle-paradox-gun.html

http://www.nramuseum.org/guns/the-galleries/theodore-roosevelt-and-elegant-arms-1880s-to-1920s/case-28-an-age-of-elegance/westley-richards-super-magnum-paradox-side-by-side-shotgun.aspx

The photo of the H&H Paradox muzzles looks more like conventional rifling with a ramp on the trailing side of the rifling rather than the ratchet style Fosbery patented:

http://www.classicshooting.com/blogs/reading/17662636-definition-of-a-paradox-gun

Longbow

The picture on that last website is a drawing, not a photograph, and possibly just how someone imagines the Paradox rifling might look. You often don't get a good look into muzzles in a museum. I haven't read the patent, but it is likely that the ratchet rifling is something Fosbery and Hollands, as his assignees, could stop others using while it remained in force.

The "Paradox" book looks good, and Fosbery was an interesting man, with a lot of other good work behind him. I have fond memories of a friend's inherited Webley-Fosbery automatic revolver, which his grandfather carried in the First World War. But there are cheaper places to buy the book on www.bookfinder.com (http://www.bookfinder.com) , part of my life support system, than that website.

[longbow]

BIS:

Yes, you are right. The patent drawing does look different than the photos of Paradox muzzles sent to me by Holland & Holland:

180365180366

Here the rifling appears to have a bit of a flat or gently sloping land then a radiused "scoop" back to the next land with vertical face rather than the more exaggerated scoop in the patent drawing. The "scoops" being a ramped groove.

Not quite sure what purpose that serves over conventional rifling other than possibly less distortion to the boolit?

Also not sure why some other company could not use the idea but with conventional rifling unless the patent included the smoothbore with short rifled choke. In the end there were apparently several "knock offs" using the same type of rifled choke.

When I asked why the twist rate is so fast at 1:30" he didn't have a good answer, just that is what they measured from original guns.

I have a copy of an old Ross Seyfried article "Holland & Holland Paradox" where he says Fosbery tested a variety of rifling with from 5 to 20 grooves and many different boolit styles and weights before settling on what we now know as Paradox rifling and boolits.

I will buy the book once I am gainfully employed again. I have always had an interest in the Paradox guns but will certainly never be able to afford one with current price being 70,000.00 pounds ($87,150.00 US) for the round action and 90,000.00 pounds ($112,000.00 US) for the standard action. A bit much for my budget!

I have not made a lot of progress on the rifled choke tube other than to modify the design a little partly to make improvements (I think) and to shorten things up some as I cannot bore as deep as I wanted but it will still be longer than the 3" rifled Paradox choke.

I did cut and anneal a piece of steel which will be turned, bored and rifled shortly. Once successfully rifled I will finish turning the outside to final dimensions and then thread. Then comes the muzzle brake and barrel adapter.

In the mean time I have made up several new smoothbore slug designs to test. Mostly rehashes of previous good tests but looking for improvement. I may get them tested this coming weekend. I hope.

Longbow

[Cap'n Morgan]

Longbow,
I wonder if the rifling profile was designed that way to aid the shot load in partly skidding the rifling (which would otherwise blow the pattern) while still being able to impart a spin on a solid projectile.

[Ballistics in Scotland]

I meant the picture you now show on the right is a drawing, or perhaps a computer enhanced photograph. People do sometimes enhance things the way they imagine, and I think Fosberry's rifling had a steep side on the side that actually turning the bullet, and a shallower slope, probably right to the next land edge, on the far side. It would, to some extent, produce fliers by deforming birdshot, with a pattern normal in the centre but thinning at the edges.

Centrifugal force would surely spread the pattern wider than the choke would make it, but it is quite a pronounced choke, and I think it would pattern rather more closely than a cylinder bore. It isn't like the typical user was going to shoot high driven pheasants with it. The danger of getting a doughnut pattern with a hole in the middle through centrifugal force is much exaggerated. For the pellets near the centre of the charge are spinning in a much smaller radius than the outsiders.

[longbow]

Cap'n Morgan and BIS:

I hadn't really thought of the shot aspect as it is of little concern to me. In my case if this rifled choke tube works the idea is that it is for slugs and a standard choke profile for shot. However in a fixed choke gun of course the effect of the rifling on the pattern would be a big concern. There are certainly less sharp corners to deform shot with the ratchet style rifling.

Now having said that, I have been thinking that if it works then it is possible that I could buy a side by with choked barrels and rifle the chokes but then I would be concerned about the rifling profile. At this point I am not going to change things and try a fancy rifling cutter to make ratchet rifling. Also, at the much slower twist I will be rifling there will be less centrifugal effect so maybe the pattern won't be affected as much as with faster twist. That would also have the issues with regulation where I have been thinking choke tubes could be made slightly eccentric then rotation set by shims or ? to bring POI of both barrels together.

Anyway, I want to try the deep rifling and slow twist so see if it works. That has been and still is the plan.

I believe that the photo on the right is actually a photo but possibly computer enhanced. I hadn't considered it to be a graphic but you may be right there. I zoomed in on it after your comment and it does look somewhat "bland" without much character like a graphic would be but there are also inconsistencies in the solder lines so hard to say.

The photo on the left is for sure a photo and shows the same rifling profile though so not much question as to what the profile is and it does look somewhat different than the patent drawing (which is what I thought you were referring to).

Also, I have to say again how impressed I am with the responses from H&H. They have sent me a 2016 brochure and price list... like I can afford one of these things! Should I ever get the money I will pay the H&H London gun room a visit for sure. In fact if we are in the UK visiting relatives, I would check out the cost of using the H&H gun range for an hour or so and see if they have a Paradox gun I could shoot. It would be nice to handle and shoot one even if I can never own one. Hey, maybe they have discounts for showroom models...

Longbow

[Ballistics in Scotland]

They used to say of the Rolls-Royce (not, I am pretty sure, as an advertising slogan) that if you have to ask how much it costs, you can't afford it. I'm sure you would find these videos interesting, especially the rifle barrel regulation:

https://www.youtube.com/watch?v=qUXoNUzAyvk

https://www.youtube.com/watch?v=RLxDRb7yWnw

https://www.youtube.com/watch?v=1itgVCzelWg

Somebody has to do it! I once visited the workshop of Ian Crudgington, who now owns George Gibbs of Bristol, and does work very, very hard to distinguish from Holland's or Purdey's at far less cost. It is amazing how the people and the workshops sound and look like ordinary technicians. But they aren't. I feel for the firms that are in that situation and relatively unrecognised, and those which have vanished in the past. It is a reputation-based world, and not always with good reason.

I recently saw someone online bemoaning the fact that Ruger couldn't supply the new firing-pin his now-discontinued Red Label needed after only 300 shots. Here is the automatic safety actuating rod from my well-worn and cheap Gibbs sidelock. It is mid-way through silver soldering a piece of high speed steel to replace the end where just applying the safety has worn it shorter. I can only guess how much shooting that took, and yet the rest of the gun was nearly as tight as it was made.



I think the purpose of the ratchet rifling in rifles was to minimise the opportunity for fouling to cling. Both the rifling forms used by Metford (one just plain very shallow and gain-twist, the other rounded) were probably better at this. But the muzzle is a place that would foul very little anyway. I agree, the purpose of it in the Paradox, which needed the rifling to be deep, was to minimise distortion of birdshot.

As to rifling the choke of an existing smoothbore, well maybe, but I wouldn't buy one sight unseen for the purpose. Smoothbore chokes and the lead to them vary considerably in length, and making them too long defeats their purpose. They operate by giving the shot an inward movement, and if the parallel section of the choke is too long, it ceases before the shot exits. I think the Paradox requires the chokes to be longer than most.

I notice that one of those advertisements posted in this thread says the person with a Paradox and a .450 Express would be armed for everything from snipe to tiger. I am not sure the same wouldn't apply to a smoothbore game gun and a .450. But it is a fascinating concept.

[longbow]

BIS:

I don't have to ask... I know I can't afford it. That applies to the Rolls Royce as well as any H&H guns. I can still admire them though.

Yes, a very tedious procedure to get the barrels regulated. What I have never figured out is why over and under guns are easier to regulate than side by side but that is what I have read. It should be the same procedure. I am a bit baffled on that one. I have always had a soft spot for side bys, they just look right. Over and unders do nothing for me.

Thanks for posting those links. That was a good watch.

I am surprised there is still so much hand work at least at roughing stages. I would have thought that CNC machines would be used where ever possible to at least rough out metal parts and wood then hand finish but it appears that much is done start to finish by hand with a few power tools. Of course we are not seeing the entire operation in those videos as well.

You may well have a point with the ratchet rifling and fouling. I have been assuming that Fosbery designed his style of rifling specifically for the Paradox guns to suit the shot and bullets being used. He may well have just chosen a suitable style of rifling that had been proven and suited his use.

Smokeless powder was already in use by the time the Paradox guns were made but BP was also still in use and his research undoubtedly started prior to common availability of smokeless powder. So Fosbery may have considered the fouling issue as well.

Not sure what the Paradox knock offs by other companies used for rifling twist, length or style but I know there were other successful guns similar to the Paradox. On that note, I should contact Westley Richards to see if they can provide any details of the Explora ball and shot guns. That would also be interesting. I also found some online books on ball and shot guns that I downloaded but have not reviewed yet.

Longbow

[Cap'n Morgan]

Yes, a very tedious procedure to get the barrels regulated. What I have never figured out is why over and under guns are easier to regulate than side by side but that is what I have read. It should be the same procedure. I am a bit baffled on that one. I have always had a soft spot for side bys, they just look right. Over and unders do nothing for me.

A side by side will vary it's impact in both the horizontal and the vertical plane depending on the loads. An over and under will only be affected in the vertical plane.

[longbow]

Cap'n Morgan:

Please indulge my ignorance. Why would a side by side vary impact in two planes and an over/under only 1 plane? The basic construction of the barrel sets is the same.

I have to think you are right because over/unders tend to be cheaper than side by sides especially in rifles but I am having trouble understanding why they are easier to regulate and/or just don't throw POI
off in two planes.

It has never made sense to me and I have never had anyone explain it to me.

On the up side of things, I have started turning and drilling (prep for boring) the choke tube. Unfortunately I am finding that I have a lack of tooling for the length of stock I am using so may have to build or buy a steady rest otherwise cuts will have to be very shallow. External turning should be fine because I can use a center but boring could be a bit difficult. If I have to I will take the choke tube to a friend who has a much bigger lathe, much better tooling and a much better skill set than I do as a machinist.

Anyway, progress is being made.

That and I just made up a bunch more smoothbore slugs to test as well. I have re-initiated the copper tube skirt slugs for round three.

Longbow

[Andrew Mason]

PM me if you need some 4140 cm, i cand send you some, just pay shipping.

[Cap'n Morgan]

Longbow,
Notice how the barrels on a double barreled shotgun are not parallel, but are set in a slight angle to compensate for the recoil moving the muzzle before the shot has left the barrel. This is because the point where the stock rest against the shoulder is below the centerline of the barrels. In a side by side the centerline(s) are slightly off in the horizontal plane as well, causing a slight sideways muzzle movement on top of the vertical lift.

That said, I would think a side by side would be less finicky to regulate, as the barrels are symmetrical and closer to the centerline in the vertical plane compared to an o/u, but I'm certainly no expert on these matters...

As for boring out your choke tube, perhaps you can get some ideas from this guy:

https://goo.gl/xpNRqW

[longbow]

Cap'n:

True enough, I hadn't thought about that or the reasons why. It seems "normal" for a side by to converge its patterns and so the tapered barrels tend to be lined up more or less parallel under the rib where it seems O/U's are more like parallel on bore centerline. I guess it would take some examination but that is how it seems to me anyway.

Regardless, I like side by's and always have so for me side by it is.

In any case, I am beginning to wonder why I picked such a hard road to follow here as I am sure there are suitable side by's with suitable screw in chokes and I could have simply made a pair of choke rifled tubes to fit. However, I have my old single shot slug gun and decided it would get an add on choke tube Pachmayr like so here I am! The single shot is the test subject to see if my rifling idea works well enough to proceed.

I have asked H&H if they have any comments on why the rifling twist in the old Paradox guns was so fast but so far no comment except that is what they measured. To my knowledge the bore guns used much slower twists in 12 bore.

Anyway, progress is being made... slowly but progress anyway. I have been out of work for the last month so have had time but find that it gets away from me as I have been out to the archery range and fishing along with catching up on other things. Funny how that works.

My big concern now is boring the bar stock because I don't have a steady rest and my lathe chuck is too small to slide the bar in half way for support so I have an overhang of about 4". I may be able to make a steady rest but there is little room for one on my small lathe. Alternately, I was thinking about making a guide tube that slides over the outside of the round bar to stabilize it while I am boring. I will drill to 5/8" diameter then bore from there. My plan is to bore to finished inside diameter of about 0.710" or a little less then cut rifling with groove diameter just under the shotgun bore diameter so about 0.010" deep rifling.

The rifling machine worked well for my test of rifling 3/4" pipe so it should be good for rifling the bar stock.

I will have a read through that book in the link you sent. Thanks for that, it looks like good info when I scanned through it.

Longbow

[longbow]

Andrew:

Thanks for the offer but I already have material for the parts. I am using an old axle out of my old Chevy truck. I annealed it and it seems like pretty tough steel. It will be a medium carbon steel at least as the axle bearings run right on the axle.

I had planned on buying some 4140 at a local machine shop but decided I would use the old axle.

Re-looking at things I will be able to put a steady rest in which will solve the unstable boring issue but I will have to build a steady rest now. They aren't terribly expensive but I am currently unemployed so will be building one not buying.

Another project! Just what I need. Oh well, once the steady rest is made that should be the last hurdle before I can finish up the choke tube. I should have looked at this some time ago and planned out what tooling I needed.

Longbow

[longbow]

Well, I kinda brought this back from the dead!

As I've mentioned on several other people's threads, I have restarted this project. Restarted in a slightly different manner but same end goal.

I decided it was going to be a lot of work and a bit much for my limited machining skills and tooling to make a Pachmayr type barrel adaptor, muzzle brake and choke tube plus I would have to make all my own choke tubes as well... so, I bought a barrel adaptor from Brownells along with a cylinder choke and a blank choke with Mossberg thread.

I bored the blank choke to 0.705" and am in the process of rifling with the intent of reaching 0.725" groove depth (or better... up to 0.729"), so 0.010"+ rifling.

The equipment and procedure is the same as used for the 3/4" pipe I experimented with at the beginning of this thread (pics are there) except I had to remake my rifling head because it was too big to fit into the choke tube. Same style just smaller.

Progress is SLOW! It appears that my cutter has dulled and I rifling is only about 0.002" to 0.003" deep so far after hours pushing and pulling on the rifling head. The current cutter is ground from a file and uses the edge of the file for cutting teeth per instructions I found. Traditionally the cutter was a hook cutter that scraped a small amount of steel from each pass through the groove. I figured the file would be more than adequate and after all, it is a file! However, my cutter is not cutting much at this point so I'm trying the acid sharpening method so I don't have to replace the cutter. So far the acid method is not working but I'll try again.

If acid doesn't bring the edges back to cutting sharpness I'll try grinding a hook edge on the cutter while it is in the rifling head (epoxied in). If one of the two methods doesn't work then i'll have to re & re the cutter. BAH! If so I my grind a hood cutter so I can sharpen it because once the file is dull, its dull. Id acid etching doesn't refresh the edge it is no good.

I am wondering if the choke tube material is particularly tough. I have read that modern choke tubes are made of stainless steel because it is more resistant to damage by steel shot. Not sure if that is common with all brands or just some and not sure why hardened stainless would be any better than hardened carbon steel. If stainless that may explain why cutting is so slow. Stainless is tough tends to work harden... depending on grade. Hmmm maybe that's why it is resistant to steel shot damage?

Anyway, I will be back at it after I get the cutter sharp or replaced. I'll post pics when I have something better than the rifled 3/4" pipe!

Longbow

[Cap'n Morgan]

Longbow

How many teeth does your cutter have? Too many teeth engaging at a time will need quite some pressure to get the individual teeth to "bite". As you write above, traditional cutters normally is a single-tooth affair.

Maybe it would probably be possible to etch the rifling? I once fooled around with "King's Water" acid to put "engraving" patterns on a shotgun; The part is heated slightly, and a thin layer of beeswax smeared out on the surface. The pattern is drawn using a machinist scribe and the acid is applied to the surface (taking great care only to cover the pattern) My "engraving" turned out so-so, but that was more to my lack of artistic skill than the actual etching process.

Various rifling methods described here:http://firearmshistory.blogspot.com/2010/05/rifling-manufacturing-electro-chemical.html

[centershot]

longbow, in my experience (as a machinist for over 20 years), I'd rather sit through a root-canal procedure than work with stainless steel. OK, a bit of an exaggeration, but you are absolutely correct when you said that SS was a tough material to work with. It IS tough, not particularly hard, but tough. It doesn't machine as easily as 4140 or any of the more popular "gun-type" steels, it's a PITA for sure! Cap'n Morgan is probably correct, a single tooth hook-type cutter is probably the best choice. You'll have to play with the angle on the cutting face to find what works best. Go slow, you'll get there!

[W.R.Buchanan]

LB: OK you need to grind a single tooth cutter out of a Hi Speed Steel tool blank, available at any industrial supply for a few $.

The problem with your file cutter is that you are spreading the cutting force (that which pushes the cutter into the work ) out over several teeth and thus it will take forever as you are essentially wearing the grove into the material as opposed to cutting it. A file is hard enough but spreading the force out over many teeth reduces the force on any one tooth to next to nothing.

Also when you push the cutter back thru the cut for a new stroke you will dull the cutter. This is why you need a HS Steel cutter as it can take that .

Randy

The Stainless they use is 17-4 and it is not any harder to cut than 4130, and you'll get a nicer finish.

[longbow]

I used the chunk of file as recommended on some site about rifling. I know the traditional cutter was a single hook cutter but the way this thing works I doubt a single tooth cutter will be suitable because it will have to exit the material totally and will spring up a bit so will hang up on the next stroke.

The file started out well and was removing material quite well but it dulled fairly quickly so as Cap'n Morgan states with load over many teeth the pressure against the cutter has to be quite high and removal rate has dropped significantly now.

I see that Bookie at Toad Hall used saw teeth which is a thought (power hacksaw blade?). What I will try next is to cut hook teeth into the file with a carbide cutter. If I set them up with flat faces I can use a diamond hone to sharpen the teeth frequently. I am thinking 3 teeth should allow one tooth to exit while two remain in the groove so not allowing that spring and catch issue. Only two will be cutting but they should be close enough in height that letting one exit should be an issue (I hope!).

If that doesn't work then I'll pick up some high speed steel and try Randy's suggestion.

I am currently about 1/3 to 1/2 depth on the rifling so not a total failure to cut. It started fast and now has tapered off. If I made another file cutter or preferably get the current one sharp with the acid bath then I should be able to finish this choke tube reasonably quickly. If I do another I may try a different approach with the cutter... and may have to to finish this one.

I am thinking the hook cutter with 3 teeth is the easiest to try. However, it won't be real easy to replace the current cutter with exactly the same width new cutter. If it is even a few tenths wider it will bind in the grooves. Better to be a bit narrower.

Also, I'll have to set the cutter into a groove then reassemble things to maintain timing and that will be a bit of a pain!

I did have trouble boring the blank choke tube and did not get as smooth a finish as I would have liked plus there was a spot in the tube that seemed softer than the rest and I see a noticeable groove there. Not likely more than a thou or so different diameter but obvious to the eye with a light in the tube. I tried honing and got most of it but... Of course that is gone in the grooves now but I'll have to lap to remove from the lands. It may not hurt anything but I don't like it.

I will keep at it until done this time though.

Longbow

[longbow]

Hah! Found it whilst looking for rifling cutter alternatives:

https://www.bevfitchett.us/antique-rifling-machine-2/cutter.html

That's Bookie using a piece of file!

At his site he uses a piece of saw blade with quite coarse teeth. I have some power hacksaw blade but I doubt its wide enough. I'll double check but I am sure it won't be as wide as the file I started with.

I am now waffling between hook cutter and scraper style. Scraper style is likely slower going but should allow a single point cutter to leave the groove and not hang up on re-entry. I think for hook cutter the way I am set up I will need at least two teeth so one can leave then re-enter without hanging up on the edge.

I'll figure it out!

Longbow

[tomme boy]

What does your cutter look like?

Would you be able to rig up a tooth off a circular saw blade with a carbide tip?

Heck the ones at Harber Freight are pretty cheap.

[longbow]

My cutter looks just like the one in the Bev Fitchett link... it is a piece of file with the faces ground off leaving the edge as a multi tooth cutter. Easy to make but not as effective as i would have thought considering the source. Oh well!

To be honest there is an idea I hadn't thought of is a circular saw blade. If the carbide is narrow enough and not too long it might work and if so the carbide wouldn't likely dull for a whole choke tube or maybe even a whole barrel. Obviously cutting speeds are low when cutting by hand.

For now I think I am stuck with either replacing the cutter I have in kind or possibly making a hook or scraper style cutter out of a file or high speed steel as Randy suggested. Since I don't have easy access to tool steels, unless possibly I get something used from a local shop and grind it to shape, I'll likely use a file and carefully grind a cutter out of it. As I said, I am at least 1/3 the way there so at worst I'll have to make a third cutter to get the full depth of rifling. They really aren't that hard to make but I do have to make sure they are pretty much the same length and for sure the same width to fit the partially cut grooves.

If I do this again (IF!) I'll look at the circular saw blade Idea. Or possibly another source of carbide cutter. Good idea!

Longbow

[missionary5155]

Greetings
Keep on Keeping on my friend ! I can remember when this was just a dream. 1/3 is a .333 batting average ! That is light years down the way from a dream.

[longbow]

Mike:

It has been a long haul! Actually, I got started this several years ago but life got in the way so it got dropped. First the dog was winding down so I spent time with the poor old guy then my mother's health started to deteriorate so that distracted me even more then there were other issues so I just didn't get back to it. But I'm back on it now and making good progress.

One thing that I do not like is that the factory blank choke tube is very short. It really may not matter because the twist is so slow but I'd rather have 3" or 4" of rifled choke tube then about 2". We will see what we will see.

I see you are back in Peru again for a bit. Do you do much shooting there? I recall you saying you had a place to shoot but I'd guess reloading supplies are scarce? What guns/calibers do the locals use?

Take care.

Longbow

[longbow]

Disaster has befallen me!

I remade the cutter to a single tooth hook style cutter and it worked... a little too well! It cut well from the get go but tended to grab and stop so requiring a bit of force to get moving again, in either direction, I am guessing that there was enough force at some point that the choke tube slipped so became out of time with the cutter and it removed the sides of the lands already formed.

Since I had the bore at a small dimension I may be able to salvage the choke tube by matching up to old grove then cutting to full depth . The lands may be a bit ratty or I may be able to bore to decent condition and still have enough rifling depth. We'll see!

Regardless I will regrind the hook cutter to 90 degrees or maybe slightly negative so it is a scrape cutter and not likely to grab. I ground it to 5 degree positive rake per internet instructions. I kinda wondered if I should have gone with 90 degrees for scrape cutting! Now I know. Maybe even a couple of degrees negative would be best. I'll try 90 in the botched choke tube to see how it does.

So, I went from not aggressive enough cutter to too aggressive a cutter!

Here is a pic of the original style cutter from a piece of file using edge of file teeth and my wooden rifling head with the hook cutter epoxied in (shim papers go between the shoe and head):

232020

Hah! That hook cutter looks kinda poorly in the photo but does it cut! It takes curls of metal out! The rifling machine and cutter work if only I could get things right! Actually the file edge did well rifling the piece of pipe for a test. I only went about 0.005" rifling but it was clean and sharp.

This stainless didn't like the file much. The hook cutter certainly cut it but a bit too much. I'll dial it back and try again.

Longbow

[Cap'n Morgan]

Longbow.

When broaching it's important the relief or clearance angle (that's the angle between your rifling and the top of the tooth) is rather small (between 0.5 - 3 degrees) otherwise the tool will chatter - especially when the tool has a large rake angle (hook-shaped) I learned that lesson the hard way when working as a tool grinder.

[longbow]

Cap'n Morgan:

I didn't get any chatter at all but I did get some grabbing which when it happened required a firm tug on the handle to get moving again. I tried pushing back which worked sometimes but not others.

Possibly the lack of chatter is because my back rake was ground at 5 degrees but was actually more like 3 degrees because I tipped the nose of the cutter down a bit when I epoxied it in. That also increased the rake of the cutting edge which may have added to the grabbing.

The wood rifling head is a bit springy of course as are the paper shims but it all works quite well... other than I screwed up the choke tube!

The hook cutter cut amazingly well but when it grabbed and I tugged I am guessing I managed to move the choke tube a bit under the clamp so next pass took a bit of the side of the lands as I went around. I was getting nice curls of metal so it cut pretty well but was unfortunately cutting lands as well as grooves! A better clamp would help of course but you can only squeeze a thin walled choke tube so much before it distorts. I think better to solve the cutter grabbing issue.

I am thinking that a 0 rake of maybe 1 or 2 degrees negative would solve the grabbing and make it a scrape cutter. I did try a negative edge on an old file I ground like a scraper and the sharp edge did take metal off pretty well... fine shavings but consistent and clean. It would certainly take longer to rifle but if it works I don't care.

I may have enough meat left in this choke tube to get a decently rifled bore but if so the rifling won't be as deep as I planned.

Hard lesson learned (I think!). Best to scrape slowly and not get grabbing than to work faster and mess up the choke tube... though that was't the intent. The file cutter basically quit cutting and as Randy commented, I was "wearing" the rifling into existence. I'll try the scraper idea next. If it works, and this slow twist rifling works, I'll make another, better rifled choke tube.

In the mean time. I decided to modify my 7/8 oz. Lee slug mould to add a stem for screwing wads to. Now that turned out perfectly! I am about to start a new thread with pics.

Longbow

[missionary5155]

I have no doubts 300+ years ago men were working out the same details in small shops all along the colonies. Least today the availability of communication helps us all to learn and think and see.

[longbow]

Yes, Mike! Speaking of lost arts! Maybe not lost but but modern barrel making is a far cry from the old hand cut barrels. Those old guys knew what they were doing and did it well!

I am sure they had all this worked out 300 years ago because they made almost the whole rig out of wood with a case hardened cutter all made by hand as in ~ no bench grinder, Dremel, factory made files, Redi-Rod, or other conveniences.

I started with the edge of a file per Toad Hall Rifleshop directions and that did cut rifling in the 3/4" pipe pretty well (my first post in the thread). I only went about 1/2 depth as I was just proving in principle.

However, when I tried rifling this factory choke tube the file edge was inconsistent, grabbing sometimes but mostly sliding pretty easily and not cutting much. When I went to the 5 degree positive rake single point cutter the situation reversed! Fast! That cutter took out curls of metal and started pretty well but I suspect as it formed the groove and made full contact the chip was a bit too much so it stuck requiring significant effort to get moving again.

During the stick and pull harder bit the choke tube must have moved under the clamp so was then out of time. Likely a lesson learned long ago as well "Clamp that barrel down hard boy!" I can hear being yelled at the apprentice.

From these recent experiences though I have to think that 0 to slightly negative rake tools were most likely use in hand rifling. Scraping may be slower but I bet it is cleaner and dependable without the sticking issue. I'll find out as I will continue on this choke tube to see if it works. As I said, there may yet be enough meat to get usable rifling though it won't be as deep as I wanted. Still worth trying.

Longbow