Punt gun build

[Anth6568]

I'm very interested in sharing some thoughts on this subject.

 

After reading many books and talking to friends for advice, I'm getting very close to completing my build of my own working punt gun.

 

At the minute the barrel is a pure cylinder (honed true) from one end to the other, and will be of a breech type rather than muzzle loader and is 1.5" in bore.

 

In many books it states that the bore should be relieved at the breech end, tight for the main part and then relieved towards the end.

 

Could I ask all the punt gunners on this site if they could share some thoughts on this matter as I'm really interested in what you have and what design seems to work best.

 

Regards

 

T

[Old farrier]

Hi

Sorry haven't got a clue on this

But wow what a project wishing you all the best with it

Hope you took a few pictures and will post when your finished

All the best

Of

[mudpatten]

Most modern breach loaders are a true cylinder throughout their length since many are made from pre bored hydraulic steel tube and the art of relief boring is all but lost, but are none the worse for that.

 

Having said that, I regularly shoot with a relief bored Clayton muzzle loader which is the hardest shooting and best paterning punt gun I`ve ever seen. It was made circa 1850 when relief boring was still properly understood, unfortunately I`ve never attempted to measure exactly what the barrel`s internal dimensions actually are so I regret that I can`t help you there. You can certainly feel the constrictions and the eased parts of the bore when loading the card wads with the ramrod.

 

Were I in your shoes I would`nt lose too much sleep about it. My only advice would be to avoid choke boring in a punt gun. Learn to get up close to the birds and do`nt rely on the imagined benefits of choke to give extra range.

 

A bit late now, but can I ask how long is the barrel of your gun? The length, or at least the length in relation to the bore size, may have a significant effect on it`s shooting qualities.

Edited March 31, 2014 by mudpatten

[Anth6568]

Thanks Mudpatten,

 

The bore is 1.5" and it's 8ft long. I don't think that it will be getting any shorter to be honest.

 

I'm wondering if the constriction is only good for BP, as modern shotgun barrels are the opposite?

 

Does any one else have a view on this?

Edited March 31, 2014 by Anth6568

[mudpatten]

At 8ft for an 1.5" gun you`re right at the lower limit for good powder combustion. It will work quite adequately but would shoot harder if it was a foot or two longer.

 

I don`t quite understand your question mate.

[Anth6568]

Mudpatten,

 

With regards to the length, that's really interesting. How did you come to this conclusion?

Does a certain amount of powder require a certain amount of space to burn correctly and to achieve its highest pressure?

 

Regards

 

T

[mudpatten]

It depends on a large number of variables, not least the size of the grain of black powder and the method of ignition.

 

A lot of work was done on this in the distant past, in the days when a muzzle loader was the only option. On my part of the coast longer barreled muzzle loaders where very much in evidence with guns up to 12 feet long not being uncommon. Long story short, this followed on from work done in Portsmouth Dockyard and the HMS Excellent Naval gunnery school.

 

Punt guns became progressively shorter with improvements in the manufacture of black powder and of the quality of steel used in the making of the guns. Sadly, Sir Ralph Payne Galwey, a man whose dark shadow was cast long upon puntgunning advocated the use of shorter barreled guns and his ideas seem to have stuck. I also have the regular use of an RPG style gun and it does not shoot well at all producing a disproportionate number of cripples despite keeping the range short.

 

One thing I do agree with RPG over, is that M/L guns often shoot better than B/L guns. This may have a lot to do with the ignition. A M/L gun will use a relatively cool percussion cap to ignite a priming charge which will cross the breach face of the gun and ignite the powder from the bottom of the charge. A B/L gun, often using a .32 blank will blast a hot primer upwards and through the powder charge causing it to burn from the middle outwards. B/L guns are generally accepted to recoil harder than M/Loaders and often go off with an audible crack instead of a sonorous boom.

 

To partly answer your original question, if I had a modern B/L gun I would`nt worry about trying to relief bore the barrel but I would spend some time experimenting with the grain size of the powder, cannon size grain for preferrence,working down to Col. Hawkers grain and reducing the ferocity of the ignition by using a .22 black powder blank instead of a .32.

Edited April 1, 2014 by mudpatten

[Anth6568]

A great read Mudpatten,

 

This just gets better and better. Can I ask what size barrel is on the RPG gun that you shoot often?

 

I've always thought that there is something in the study of the primer. I sort of came to this conclusion whilst I've been reloading 10-12b carts. If you use hot primers it effects the pressure and velocity some what, some mix powders to create certain effects.

 

With regards to the effect of the ignition between ML & BL, I totally agree with your conclusion. I have just thought of a way how to solve that with the BL. A simple design to force the ignition flash side ways across the base of the powder instead of through the centre.

 

I could also make adapters for the different size of carts .22 ( would need to make a new breach plug with an offset firing pin) but the .32 & .380 is easy enough. A friend of mine recommended that I use .32 as .380 is too strong.

 

Can I ask what sort of BP you would recommend with the type of barrel I have and also a supplier?

 

Regards

 

T

Edited April 1, 2014 by Anth6568

[Popgun]

I have 4 Puntguns 2 muzzel loaders and 2 breech loaders the breech loaders are 1 1/2'' and the muzzel loaders are 1 3/8''the long muzzel loader has a 9' 6'' barrel and is a very hard shooting gun,the other muzzel loader has a 8' 6''barrel and shoots well the load for both these guns is 14 ozs of shot and 2 3/4 ozs of hawkers grain black powder,1 of the breech loaders has a 9 ' barrel the gun uses 32 blanks which are loaded half full with fine grain black powder, the load for this gun is 3 3/4 ozs hawkers grain and 20 ozs of shot this gun was built by Blands and shoots shoots well. the other breech loader I had built in the 80s its barrel is 7' 10'' and the gun is 140 pounds and shoots the same load as the bland which go'es 95 pounds this is the weakest shooting gun of the lot it uses 38 blanks half loaded with black powder Ive shot a lot of birds with this gun but it no where near as hard shooting as the long muzzel loader which is recesed bored. I am sure that muzzel loaders shoot a lot harder than breech loader and the muzzel loaders are a lot lighter than the breech loaders the long gun is 78 pounds which is very near half that of the modern breech loader. thats my take on it for what it's worth.

Pat.

[Anth6568]

Sounds like there is something in the performance of the ML Popgun. You mentioned that the charge as a whole was lighter than the BL but shot better. Granted the barrels are longer on the ML but do you think that it is the combination of type of ignition and length of barrel?

 

What sort of ignition is on the ML if you don't mind me asking?

 

Regards

 

T

Edited April 1, 2014 by Anth6568

[Popgun]

The Muzzel loaders have top hat percusion caps into a priming chamber which has fine grain black powder in it which you need to measure out after trying different measures of the priming powder the chamber has an opening threaded end and I used a pricker to push into the main charge which is loaded into nitrate paper for ease of loading this makes sure that the flash reaches the main charge. if you try out different loads of priming you will see that it makes a difference at least i think it do'es. I seem to think the puntguns allways shoot harder in very cold weather, some people say they havent noticed this so maybe it's just me.

Pat.

[mudpatten]

The RPG style B/L gun is 1 1/2" with an 8ft (or so) barrel which weighs 120 lbs and fires up to 26 oz. Despite it`s weight it is extremely lively with a full load and shoots far more comfortably and with much less drama when digesting 16 oz`s. It also has trunnions which exascerbates the problem.

 

Respectfully,you have`nt mentioned what your barrel is made from or how it`s been built and wether or not it is prooved which would make giving suggestions for powder type etc. a bit of a risky stab in the dark. A picture or knowing what shot load you propose to use would be very useful.

 

I`m sorry but I can`t help with a supplier of Black powder. In the larger grain sizes, large cannon or blasting, it`s like gold dust. We have enough for the foreseeable future but I`m not sure where we`ll be getting it from when the time comes to resupply. I too am interested to know of any suppliers.

 

Out of interest,how will you be dealing with the recoil?

Edited April 2, 2014 by mudpatten

[Anth6568]

Thanks for those comments Popgun, I wonder if any one has loaded their coarse powder on top of the fine powder to aid ignition in a BL?

[Old farrier]

Hi

I'm finding this very interesting rather new to Reloding so if these are stupid questions my appologe in advance

I assume you need a set length of a set diameter bore to burn a amount of powder to propell a shot ?

Cannon and swivel guns have shorter barrels but bigger bores so the area for maximum powder burn must be on a ratio ?

So realistically you could have a barrel to long unless you could do the calculations

Any idea of a reliable source of data ?

Sorry if there silly questions just trying to work out optimum bore size over length

All the best

Of

[Popgun]

When I was young I played with the loads on my muzzel loaders I loaded some very big powder loads but all that did was to blow unburnt powder out out of the barrel which I think just blew the pattern. if you start at 3ozs of powder to 16ozs of shot then play with the load to fit the size of the gun. Rember to much shot is a lot worse than to little shot it's just trials untill you get it right remember when you shoot at a pattern board do'nt forget about penatration it's no good having a good pattern if you do'nt have the velocty to kill your birds. hope this helps to get you started.its good fun playing with puntgun loads and if you shoot your trials inland over non wet lands you can use lead shot loads because you do'nt want to pay for non tox for pattern board shots. Pat.

[Anth6568]

Mudpatten,

 

It started as a 3 inch thick bar of 4140 steel, of 8ft in length. I then had it bored and then honed by a big firm. The barrel is now being tapered and sleeved to finish it.

 

I was thinking if using trunnions with rope to deal with the recoil.

 

I was going to start with a 3 oz charge with about 16oz of shot and work from there.

 

With regards to shot, what would you recommend, bismuth?

 

Has anyone tried steel shot in ML or BL and have they been successful?

[Popgun]

I tried steel shot from my heavy breech loader the best results were with zink plated T shot 4ozs of hawkers grain BP and 14ozs of steel T shot in a plastick cup wad I tried it at a pattern board it shot a very tight pattern to tight but playing with the cup wad could help this I shot a few duck at about 45 yards they were hit with a lot of shot and i was expecting more birds so I think the pattern never opened as well as it should. the velocity dropped of rapidly over 45 yards.my problem was I can't get the velocity up useing Black powder. there is a lad up in Scotland who says he has cracked it so maybe it is posable.

Pat.

[Old farrier]

Hi

Popgun

Thanks for the information

Very interesting on non toxic as I'm south I have to use it so it looks like very expensive pattern testing

Do you know of anyone who uses nitro powder in a big gun

Or pyrodex as a substitute for black powder

Many thanks for sharing

All the best

Of

Just put a picture of muzzle loader up

As I know other members like to see them

Hope you don't mind op

Edited April 2, 2014 by Old farrier

[mudpatten]

It sounds like your barrel is well up to strength and your suggested load of 3 oz of powder to 16 oz of shot would be an excellent starting point.

 

We`ve been using ITM or one of the other very dense ntx materials which is hellishly expensive. Although bismuth works well in shoulder gun cartridges, it has it`s problems in a punt gun. Traditionally one would use BB shot to get the down range velocity but BB in bismuth are moulded and not dropped and have a tendency to break under the extreme pressures at the bottom of the shot column in a punt gun, even if you can actually obtain the stuff!

 

Have you thought about using an underbarrel loop for taking the recoil? A quick history lesson. Most early and many later discerning punt guns were fitted with an underbarrel loop which has significant advantages over trunnions. There is no run back, the gun does not rotate upon recoil and one can use a much thinner rope. It is a method still much in use in my part of the coast. Muzzle loading naval cannon have trunnions, however, they perform a different task on the cannon and the recoil is actually taken by a form of under barrel loop. Once again Sir Ralph Payne Galwey stuck his oar in at this point and we begin increasingly to see punt guns fitted with trunnions even though they accentuate the recoil, cause the gun to "bounce", require a thick and purpose made rope which leads to all sorts of issues with contraction and rotation.

 

I don`t know of anyone who uses Pyrodex or nitro powder although some guns have been nitro proofed and work is currently being done on using nitro in an attempt to up the velocity to enable the use of steel. As Popgun says, at least one big gunner is using steel with black powder to apparently good effect. I can ask him how he loads his gun if you`re interested.

[Old farrier]

Hi

Very interested in any info

As you say the correct powder is getting harder to

Find so the way forward surely must be with alternate propellant

Thanks for your reply

Of

Have you tried any buffer with the shot or can't it be used in a muzzle loader are you using any dot of shot cup to protect the barrel

Sorry it's a lot of questions but data is hard to find

Edited April 3, 2014 by Old farrier

[Popgun]

Try This Firm For your Black Powder, Peter J Starley Oak house Birmingham road Warwick CV35 7DX phone no 0845 2266005. have a look on Google.

Pat

Edited April 3, 2014 by Popgun

[Old farrier]

Try This Firm For your Black Powder, Peter J Starley Oak house Birmingham road Warwick CV35 7DX phone no 0845 2266005.

Pat

Many thanks

Of

[Anth6568]

Mud patten,

 

I'm very interested in the facts of the loading steel shot with BP, if you could find anything out that would be very kind of you.

 

Could I also trouble you with a picture of the under barrel loop? I have seen others like spring versions but never a single loop with a thinner type of rope? It sounds really interesting? In your opinion is this method the best with regards to dealing with the recoil?

 

I have thought about ITX as it's a close second to lead but as you stated it's expensive. I did a quick estimate on the average cost per shot, it was £30 ish, does this sound normal?

 

Regards

 

T

Try This Firm For your Black Powder, Peter J Starley Oak house Birmingham road Warwick CV35 7DX phone no 0845 2266005. have a look on Google.

Pat

Thanks for the top tip!

 

Regards

 

T

Edited April 3, 2014 by Anth6568

[Old farrier]

Bottom boards

Used pine on mine mate 1/2 inch used blocks on ribs to level it and braced across with 1 x1/2 between ribs suggest a loose fit to aid removal if bailing becomes nessesary

Picture may help

Hope it's coming on well look forward to seeing a few more pictures

All the best

Of

[marsh man]

How you doing O F...........I don't think my wife would let me build a punt in our kitchen , plucking my ducks in there is about my limet , I will show her what some people use there kitchen for and maybe she will realise how understanding I am...............All the best O F.