doublegunshop.com - home Forums General Discussion Double Rifles, Paradox Guns & Gauge Rifles @ doublegunshop.com 12 Bore Rifle

I recently came into contact with a 12 bore H&H BP rifle belonging to a friend. The rifle is circa 1886. The barrels flats have London BP proofs with a a freestanding 13 (bore?). The barrels are 24&1/8 long, weigh 6 lbs 10 oz., and have .240 wall thickness at the breach end. Groove diamater is .730. Our cerrosafe cast of the chamber shows it to be 2&3/4 inch chamber. My questions are these: Is there any loading info available for this rifle? Can components be purchased? Would it be possible to load modern sabot type bullets to use in this rifle? Would it be unheard of to shooting factory 2&3/4" sabot loads in this rifle?

Thanks in advance

Nick Taxiarchis

Nick it will most likely not shoot both barrels to the same point of aim with a modern shell. There have been a couple of articles written in Double Gun Journal about these guns. I've owned two. The first thing that you need to determine is the rate of twist. This will tell you if the gun was made for round ball or conical bullets. Next the weight of the gun will tell you if it was made for light or heavy loads. Try and find the articles I believe they were written by Mr. Bell. Good luck.

There is some loading data for gauge rifles in Graeme Wright's second edition of "Shooting British Double Rifles", but it is unfortunately out of print. He's working on a third edition, I believe. Round balls and wads can be had from Track of the Wolf and black powder from the Maine Powder House. I'd start with shotgun level loads, say 3 drams or so, and work up to regulation or nosebleed, whichever occurs first.

Be careful with that nice double rifle.
Modern smokeless production loads could very likely at least damage the gun or potentially blow a barrel or worse.
Photograph the proof marks on the barrels and action flats, show us here in the thread.
There isn't a modern production load suitable for that rifle, but with a look at the proof marks, we can steer you in the right direction for getting set up to load for it.
Load data tends to be specific to the individual rifle with these nice old 19th century doubles.

What is the bore diameter?
What are the chamber measurements -- base diameter, rim diameter, diameter of chamber at the throat end..?

I own a couple of 16 bore double rifles which I've gone through and developed loads that have both of them shooting to the sights.


-Tinker

Thank you all for the responses. I'll see about pictures and whatnot. I'm back up in the frigid north for now so it may take some doing, and a bit of time.

Thanks again

Nick

double tap

NT. Regarding the H&H 12bore Rifle,I did re-check the "CerroSafe" casting you & "Dad" made,against my brass chamber gauge(made to Specs' From "1954 Rules of Proof')The Gun...Pardon Me! RIFLE does have 3" (Three Inch) Chambers....Hope You, or Dad' can find the 'Specs" for 3" Black Powder Loads!!! cc

Mr T-

Was that rifle set up for paper cases or thin brass cases?
Can you list the chamber and bore specs?

It sounds a couple pounds too light to be a seven dram roundball gun.
What's the rifling twist rate?



--Tinker

Tinker,Will give "Specs" when next in W/Shop. cc

The only cartridges we found reference to were 2&3/4" loads. most of them for paradox type guns. Only two references on full rifle loads and nothing on three inch. This is from the "usual" books and a couple period catalogs. Certainly not empirical evidence. I'll keep on the "old man", and maybe we'll be able to dig something up between us.

Tinker, I understand that load data is pretty specific for an individual rifle but am definitely no expeert on the subject. I was hopoing that rather than tracking down a mould, or going to the expense of having one made, we could sabot a big heavy .45 0r .50 cal slug so bullet weight would be close, and than work slowly up from a minimal 2&3/4" load to Steve's "nosebleed" load. I'm going from memory but the twist rate semed fast for round ball. 3" chambers puts us in a new ballpark. I'm not sure I want to be involved after the beating I received from the last rifle The Honourable Mr CC/DT had me shoot by way of "testing".

Nick

NT,
I have a 12 bore Holland 7 dram gun made in 1882.



The gun weighs 13lbs and the barrels abit over 9lbs. I use brass cases but have used plastic in the past. I have a period mold which casts both ball and a short conical in the .740 range. My gun is proofed as a 12 and has a groove diameter of .736. I too would be interested in seeing photos of your Holland. Here is a reprint of Frank Findlow's chart from his excellent article in DGJ on 12bore rifles.

Nick-

I seriously doubt that you're going to get anywhere with sabots and sub caliber bullets with this rifle.
So much to the point that I'd never bother with attempting that with the rifle myself whether it were mine or someone else's rifle.
Interior ballistics, pressure curves...
Stick to the right stuff here, Jeff Tanner will make you a custom roundball mould for under $50.00 USD and ship it to your door.


I'm interested to see photos of your chamber casts, really good photos -- contrasty enough to be able to clearly see the condition of the chamber walls on your castings.
As noted, a seven dram rifle will be much heavier that what you have there.
Three inch chambers on an H&H twelve bore rifle lead to that assumption, but considering the overall weight my sense right off the bat is that it's not a seven dram gun.
I'd like to see photos of those barrels, the barrel flats including all proof marks, and the action flats including all of the proof marks, as well as with a ruler laid on the barrel flats justified to the standing breeches.
I wonder if someone at some time has gone in there and lengthened the chambers to clean up a pitted throat.
Also I'm curious to see if it was set up for paper or thin brass cases.

On rifling twist, you'd be surprised at how many high quality brit bore rifles *set up from the factory for roundball* have 'too fast for roundball' rifling twist rate -- and shoot beautifully with roundball nonetheless.
What is the rifling profile?
How many lands?
What is the bore diameter?
Is the bore/groove the same at the muzzles as it is at the breech end?
Compare right and left barrels too, chances are that they're not exactly the same.
Are the barrels actually original equipment?

Photos please!
Can't wait to hear and the specifics on this rifle.



--Tinker

With proof marks of 13, this most likely was a "paper case gun". There may be loading/chamber information on the Holland ledger page and you should request it from Holland & Holland London.

Thanks again for all the replies.

PM, That's a great set of data I'm saving those pics for sure. Much appreciated.

Tinker, I'm just trying to get off easy with the whole sabot thing. I guess we'll have to go with the mold and do it right. It's a hefty gun, but if 9 LB barrels are typical for a 3" gun than this one isn't even close. That's a lot of extra iron. I don't know much of anything about how much a rifle should weigh based on caliber except that dbl rifles are heavy and bore rifles heavier still. All I can reference is what little experience I have shooting big bores.

You'll have to coerce the Right Honourable DT/CC about pictures as the rifle is currently residing in the Cape Neddick Gun Hospital---Dr. Trevallion , Attending. Otherwise I'll see what I can do in a month or so when I'm back in the neighborhood.

Thanks again to all for the info.

Nick

Here are photos of rifle with 3 " chamber guage.

Older Doc-

Much thanks for posting the image, still my curiosity isn't satisfied.
Do you have the rifle in your posession or can you comment on some of the questions I asked above?

Perhaps the owner of this rifle (you?) will get in touch with the maker and get their perspective on the service load.

Can you post images of the rest of the rifle?

Again, thanks!



--Tinker

I don't have the letter nor the gun. Inthe process of getting the letter.

Older Doc-

Thanks for the answer.
I'm very much enthusiastic about these light sporting bore rifles.
Please do post back to this thread when you can share more information about this rifle.

Is it yours?
Will you be hunting with it?


--Tinker

It is mine and I do want to shoot it when I can configure the right loads. Enclosed are some photos that I do have.

Older Doc-

It seems you've found a very nice 'walking around' bore rifle.
I relly do enjoy my light 16 bore double rifles.

This is an image I've shown on the site before, I include it here to encourage you to your first day of load development.

First shots in likely over 100 years, this is a light european hunting rifle...





--Tinker