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Artillery

This topic has 50 replies, 17 voices, and was last updated 9 December 2010 at 10:19 by Howard Jones.

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17 September 2009 at 20:24 #4126
Dougie Swan
Participant
@dougieswan43463
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17 September 2009 at 20:24 #43585
Dougie Swan
Participant
@dougieswan43463
Anyone out there interested in modeling artillery pieces?

Dougie
17 September 2009 at 20:47 #43587
Ian Abbott
Participant
@ianabbott31222
Only if I could use them to pick off seagulls.

Sorry

Ian
17 September 2009 at 20:57 #43589
Ian Abbott
Participant
@ianabbott31222
Seriously, yes.

I did build a ball and cap rifle thirty years ago. Bringing it from Canada into the UK was frowned upon, so I left the barrel and stock and just brought the lock. I did cheat and buy the barrel for that, as machining 30″ of rifled octagonal steel was beyond the old Randa’s capabilities.

My interest would veer in the direction of canon and small pieces from the seventeenth through the nineteenth centuries.

And of course a barrel and woodwork for a ball and cap pistol. I have some illustrations for that, but not the experience of rifling a bore.

Ian
17 September 2009 at 23:39 #43592
Graham Buxton
Participant
@grahambuxton49131
The problem is , every body made one when they where young, and if it didn’t work, why bother. Now you’re a terrorist for mentioning it, It’s going to be an f.a.c., object if it could be made to work, so it has to be made of plastercine, and then sprayed red yellow or green, so that the police don’t shoot you if it is in your hand, (but they will shoot you if you hold a table leg , so be aware.)
17 September 2009 at 23:51 #43593
Rob Manley
Participant
@robmanley79788
Dougie, i had a look at your railway gun and must say it looks stunning. If you are going to be a terrorist – do it with something that looks nicely made
18 September 2009 at 02:43 #43594
Frank Dolman
Participant
@frankdolman72357
Dougie Swan’s 9.2″ railway gun looks wonderful. What scale is it, Dougie? And how much does it weigh? Are you going to write it up?
18 September 2009 at 07:27 #43598
Speedy
Participant
@speedy
Dougie, truly amazing work on the railway gun.

I am based in Australia and we do not have the insane laws that England suffers from. I have built a few muzzle loader cannons as presents for friends and for own amusement and am working on a full scale volley gun with a pintle mount. Also have an Armstrong 64 pr in 1/10 scale on the backburner.
18 September 2009 at 12:17 #43609
Ian S C
Participant
@iansc
Got a proof fired model 9 pounder cannon sitting on a shelf about 3M away from me,it takes .38 cal ball.Didn’t some model engineers during ww2 make parts for Sten guns(the barrel is short enough you could prob have drilled that too).Steve didn’t they have a big collection ie people handing in certain types of firearm a few years ago.I’v got a few mates into 12″:1ft guns from pistols and bren guns to 25 pounder,could be handy if one needed to get measurements to make a model.They did away with licencing guns here,the shooter/owner is licenced and the police have no idea how many guns in the country.
18 September 2009 at 12:45 #43613
Dougie Swan
Participant
@dougieswan43463
Thanks for the comments on the railway gun.

It is in 3.5″ gauge, 35″ buffer to buffer and the barrel is 27″ long, as for the weight all I can say is its getting too heavy to move when its in one piece. Its not finished yet, I still have the crew platform to fit and the shell hoist to make.

I’m hoping to have it complete by Christmas. The bore is 9/16″ but is not clear all the way through as that would make it, as someone has commented, a firearm,(I have a FAC,but I dont think the local enquiry officer would wear it if I asked to have it put on my licence for deer stalking !! )

Ive been corresponding with the editor regarding doing an article and have some drawings already done but the problem is I dont use drawings, I do a general arrangement to get the basics then make the rest up as I go along. I am trying to get a complete set together but some of the parts like the screw breech were made about two years ago and took a lot of trial and error to get the sequence of cutting right. Once the winter comes and its too cold to go to the workshop then I’ll try to get the drawings up to date

I’ll try to take some more pics with an uncluttered background and post them

Dougie
21 September 2009 at 09:59 #43675
Speedy
Participant
@speedy
Ian,

Yes they had a steal back (sorry buy back) in 1996 for semi auto longarms of all kinds, centrefire, rimfire and shotguns. In 2003 they went for handguns shorter than 5 inches and bigger calibre than 38. The only good to come from that was they formalized black powder and muzzle loading cannons in the most open category Category A. That means as long as we keep the barrel under 1200 mm in length and it is in some way a replica of an historical muzzle loader, no issues with the government or police even if it fires a 2 inch shell. It must be licensed but to my knowledge no one has ever been refused an application.

Taking it further, making a scale model of an artillery piece has no licensing issues whatsoever if we do not drill the fuze hole or if a scale breech loader there is no firing mechanism. They are just scale models in the eyes of the law. I and other makers of cannons in OZ have a great time and no legal problems.

Back to the making of them though, Dougie please publish a description of the procedure for making an interrupted thread. I remember a series of articles in Model Engineer in May 2005 wherein the author (David Wilcox) made a scale model of a 5.5 inch breech loader that included an interrupted thread. I got the issue with the last part of the three part article and of course could not get the missing issues for love or money. If anyone has the copies concerned I would love to get them.
21 September 2009 at 10:06 #43676
Speedy
Participant
@speedy
Dougie,

Further question please. What do you use for rivets? I use escutcheon nails they are brass and about 1.6mm in diameter, but so tedious to put in one at a time. Any ideas or improvements you could recommend, i cannot believe how many rivets you have on the railway gun, i remain in awe of your workmanship and patience.

regards
21 September 2009 at 17:18 #43683
Dougie Swan
Participant
@dougieswan43463
Lets start with the rivets, all of them in the pictures so far are 1/16 iron,all of them are put in individually, if the reverse of the head cant be seen then they are countersunk but if both sides are visible then they are formed and domed with some snaps. The main body side frames, top deck and the bogie supports at each end are held together with the rivets, I had to make various supports/ building boards to help support everything while riveting together. So far I’ve used about 1500 1/16 rivets and the next stages are held together with 3/64 rivets lots of them to do too!!. Once all the holes are drilled and everything set up on the supports I made it doesnt take long to get a rhythm going.

As for interrupted thread breech screws, the easiest method is to first cut or use a nut and bolt of the thread size you need, I’ve found that BSP pipe threads and NPT both in straight and taper form are suitable. What I do when using either of the above threads is screw both together and hold in the chuck so that I can turn the o/d to whatever size I need to fit into a socket in the breech end of the barrel. At the same time centre and drill through the bolt to take a mandrel. Next seperate the two parts then re- assemble with loctite, turn a mandrell to fit the hole in the bolt and secure with loctite again, this is to enable the whole assembly to be mounted in the rotary table on the mill. I’ve ran out of space here so Ill start another post

Dougie
21 September 2009 at 17:53 #43684
Dougie Swan
Participant
@dougieswan43463
Breech thread part two

Once the whole lot is set up in the mill I use the rotary table to cut away alternate segments of the whole lot. Set up and centre under the cutter, use the smallest you can to keep the radius in the corners small, then cut away both the nut and bolt to under the core diameter of the bolt and index round for 60 degrees removing everything in the 60 degree arc. So the sequence continues like this, from 0 – 60 cut, 60 – 120, skip, 120 – 180 cut, 180 – 240, skip, 240 – 300, cut, 300 – 360 skip. This will leave a six segmented interrupted thread in its locked position. All that remains is to heat up and separate the parts, remember to mark which segments go together so that on assembly into the barrel they can be lined up.

The breech operating lever is set up to give 1/6th of a turn as it is pulled to twist and unlock the threads before the rest of the movement swings the breech out of battery The screw rotates on the hole drilled for the mandrel once it is assembled onto the breech block

The coastal defence gun in my gallery uses this system, if I was inclined I would have made this with a working though not to scale hammer and firing mechanism with a breech to take .38 cal blanks and of course removable so as not to land my a** in prison in case anyone checked, but that would be illegal in this great land of ours

Dougie
21 September 2009 at 18:24 #43686
mgj
Participant
@mgj
You could also cut it with a shaper or slotter from head on. One of the Hemingway slotters and a dividing head would do that.

What was the ignition system on the originals – a vent tube presumably?

I’m just wondering whether we really are into FACs? I cannot believe that every yacht club in the country with its little signalling gun has an FAC? And this isn’t a gun – its a model. And there are collectors exemptions. What about all the museum models – they all have FACs?

There is an awful lot of unsubstantiated rubbish spouted in the deer world about FACs, especially on the DSC courses by people who really don’t have a full command of the facts, and things pass into lore. It might be worth talking to a real expert on the matter.(Speaking as someone who stalked commercially for 15 years – and mercifully got out!)

And no I’m not qualified to give an opinion on the legalities – but I do for example remember the tiswas that BASC got into about the Hunting bill, and there was a many paged article about how it was going to affect all the many game shooters who weren’t going to be able to use their dogs and the effect it would have on owners and field triallers, and the cruelty of not recovering birds. Except that the Bill was about hunting mammals, and so far as I know, birds are not mammals, and using a dog to recover a wounded bird is not the prmary means of catching. Nor even is using tracking dogs for deer.

Talk to the experts if you want a “working” version.
21 September 2009 at 18:53 #43687
Dougie Swan
Participant
@dougieswan43463
Hi Meyrick, from what I can gather the ignition was by vent tube, either electric or percussion, I’m not sure if each system was interchangeable or if it was one or the other.

The info I have is very sketchy, the IWM sent me some diagrams but refused to send others that they have as they were “too fragile” to copy

Dougie
21 September 2009 at 23:16 #43691
mgj
Participant
@mgj
I doubt they’d be interchangeable Dougie. I’m no expert on vent tubes other than the 120gun uses a magazine of electrically fired vent tubes.

Basically the vent tube had an earthed body and an insulated centre contact – it looked like a .50″ cartridge – more like one of the Infantry COMBAT/WOMBAT 50 Springfield spotter rounds than a 50 BMG. That got fed (or not as was often the case)from a rifle type magazine into the nose of the FNA – the rather antiquely named Firing Needle Assembly. (Rather like a Mauser bolt face on a vertically sliding breech) A central contact would then make electrical contact, and you would pull the trigger when ready. That lit the gunpowder in the tube.

As far as I know the mechanical vent tubes used a hammer or lock to fire a small primer which fired the gunpowder charge in the tube. (going by the US M110 – 155mm Counter Battery and 8″ howitzers.) So the probability is that the mechanical systems woulnd’t have had any electrickery to the breech – just a lanyard. Some of the bigger guns had hydraulic breech opening mechs.I think the rotation of the breech locking mech would cock the vent tube firing lock, but the vent tube itself would be manually loaded and manually extracted.

Gunpowder was used because its very “flameful” and full of burning particles which are good at penetrating the cloth covering igniter pads on bagged charges.

Everything I know about vent tubes!!!
22 September 2009 at 01:50 #43694
Speedy
Participant
@speedy
Dougie,

Thank you for the succinct post on your methods to make an interrupted thread. I had considered the use of my rotary table but the use of an existing bolt and nut would save a lot of time and eliminate the alignment problems I had envisaged.

Now for the stupid question. Where do you get your rivets? I have often enquired here in OZ but no such luck for 1/16 rivets from the normal suppliers.

regards
23 September 2009 at 07:57 #43740
Dougie Swan
Participant
@dougieswan43463
The supplier I use most often is ITEMS, a specialist BA screw supplier, unforunatley they do not have a website but the tel and fax numbers are as follows

Tel 01427848880 Fax same

There is also a company called The Rivet Supply Company, Google Sapphireproducts both of these supply rivets in steel at 1/16″

I have scanned the articles and will send in an email

Dougie
23 September 2009 at 19:57 #43759
Ian Abbott
Participant
@ianabbott31222
Does anyone have information on rifling? It’s something that I’ve never approached, stuff that I made decades ago either had smooth bores or the one muzzle loading long gun was too big to consider, so it had a bought barrel.

Something that I might have a go at are drawings of a miniature starting pistol about four inches long, in the shape of a muzzle loader which I have. I’ve often thought of making a copy and sharing the plans. The original is probably from around WWI, and probably involves pretty much all hand work, not much scope for machining past a few drilled holes.

Ian
23 September 2009 at 21:00 #43766
mgj
Participant
@mgj
What do you need to know.

Depth – typically .008 on dia for our sizes such as 30 cal = .308 groove to groove ..303 =.311 groove to groove. .303 land to land. .270/277 etc.If you look up SAAMI they will give you all the tolerances etc

Typical steel in US nomenclature is 4130. There will be a UK equivalent. Its not a “special” gun steel. (there isn’t such a thing really) Its just a medium carbon, workhardening engineering steel like many others.

Twist rate depends on velocity and projectile length. The longer the proj (length to diameter ratio) the greater the twist rate. The higher the MV the lower the twist rate, so you need to get this right. It varies considerably, so you would need to look at something in your class. Long arms with an MV of about 2500-300fps are about 1:9 – 1:10 twist rate.

How to make – well you can hammer forge onto an externally rifled mandrel with a rotary hammer if you are a professional, or for a one off you’d be best off making a broach of the right size with offset cutters, and a guided tail of the right twist. Or you can single point cut and index. The cutter is on the end of a rod, and the rod is externally” “rifled” and passes through a stationary “nut”. Whip it up and down the barrel.

If you want to make an accelerating twist, then you have to cut the rifling with a cutter moving down an externally rifled guide connected to a cam, and at a point part way down the bore the cam comes in and turns the guide, accelerating the twist towards the muzzle. ADEN guns had that.

In principle its not that difficult. The barrel doesn’t even have to be terribly straight. You don’t want it lumpy along the bore, but a (little) bit of a banana doesn’t matter, so long at it remains consistent (tank barrels warp by whole inches along their length due to differential heating in a breeze). For the initial drilling op you want a deep worm gun drill, which are easily bought on special order – I have several, not for guns I might add, but for drilling various deep straight holes in milling machine quills etc.The automotive industry uses them a lot for doing oil holes etc.They are in the catalogues of people like Dormer – specialist, hardly rare, but not the easiest of things to use.

In this country at least, if it were recognisably a pistol, and rifled, you might have a difficulty with the legalities. And proof? However, thats an area I am simply not competent to comment on and you would need to ask an expert. (never tried, got no interest)

A word of warning, or a suggestion. If you are going to make one of these things and actually fire it using a nitro propellant, be aware that loading a pressure vessel up to 19tons/sq inch near ones face is a potentially hazardous activity. Worth making sure you have the maffs right before proceeding? (Especially with things like locking lugs on which the integrity of the whole affair depends)
23 September 2009 at 21:31 #43768
Speedy
Participant
@speedy
The best example of how to rifle a blind hole, like you would have in a muzzle loader, that I know of is contained in a series of articles at Greybeards Outdoors Cannon Forum. These guys are mostly American and deal a lot in full size cannons, but there is a fair percentage of scale model makers (including one of the moderators) and often a lot of info that just cannot be obtained anywhere else on the subject of building muzzle loading cannon.

Please see the following address for info on how to make a rifling machine.

http://www.go2gbo.com/forums//index.php?topic=108012.0

regards
23 September 2009 at 23:35 #43771
chris stephens
Participant
@chrisstephens63393
Hi guys,

I came across this in an old(ish) book and thought it might be interesting, from a metallurgical point of view of course.

chris stephens
24 September 2009 at 20:03 #43804
Ian Abbott
Participant
@ianabbott31222
Thanks, the rifling sounds straight forward then, but I doubt that I’d be making a working weapon. However, it it does need to look right when one looks down the barrel.

Ian
25 April 2010 at 16:28 #51124
Dougie Swan
Participant
@dougieswan43463
To all the people who were interested when I posted the first pics in this thread check out the finished article.

Rough dimensions are :-

Guage 3.5″

Length 36″

Width 6.5″

Barrel 27″

See you at Harrogate

Dougie
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