One block of steel

[sambarhunter]

Computer controlled machining,drilling and rifling and then chambering...why do we need two individual barrels soldered together?

 

[bruce moulds]

because solder is adjustable?
bruce.

 

[Shootist43]

Sambarhunter, that is a nice thought. But like Bruce said, solder is adjustable. If a CNC Double was possible, my thoughts are that we would have seen one by now.

 

[mark-hunter]

Check cheap russian doubles. No soldering, barrels are user adjustable by screw.

 

[Alistair]

Interestingly, a few shotgun makers are now going down the single piece cnc barrel route. The ones I know of are Longthorne in the UK, and I think maybe Fausti.

The methodology is sound and it makes logical sense, I suppose the only challenge is can you do it consistently enough that the barrels shoot to the same point of aim? I'm not convinced.

Theres also the consideration that with a single piece barrel set, you can't re-regulate. It'll only ever group with whatever it was set with from the factory which could become a problem is supply of the 'correct' ammo dried up.

 

[Hogpatrol]

It's doable but would the market size justify the capital expenditures and training? I would surmise that custom handloaded ammo would also be required.

 

[spike.t]

To regulate a double rifle the solder is heated to adjust point of impact. I shot a .470 rigby for Paul one time to regulate it...watching the gentleman working on it after two shots through each barrel to slowly bring the shots together was very interesting.... Bit of wizardry I promise you....he even looked like one....not too many who can do it. There was another cheaper brand Paul sold that were regulated using some technical method... can't remember what it was , but some shot fine whereas Paul had to re regulate a percentage of them as didn't shoot very well...

 

[Shootist43]

Shotguns are one thing, rifles are another.

 

[IvW]

...cheap russian doubles.

If they where any good each PH would use one....

 

[AZDAVE]

You can by a yugo or you can buy a BMW. Both are cars but you get what you pay for.

 

[Opposite Pole]

Check cheap russian doubles. No soldering, barrels are user adjustable by screw.

Some not so cheap and not so Russian doubles also allow it in some calibers. Like Krieghoff - up to 9.3 or 375 not sure which one, regulation is adjusted by a screw. In bigger boomers the barrels are soldered.

 

[sambarhunter]

I am no metal machinist but with all of this super modern computer driven metal machinery that I have seen on youtube and some of it seemingly impossible etc I can see a billet of steel bored out with two holes after every possible combination of all things known to man are fed into the computer has been fed into the machine. Surely two holes can be bored like so and the regulation programmed in to a specific bullet/weight/BC .
Sticking ones head in the sand saying it cant be done isnt ideal thinking in my book.

I would like to see more on this Alistair,have you any links?

The ones I know of are Longthorne in the UK, and I think maybe Fausti.

 

[sambarhunter]

Alistair you got me searching and it took two clicks,thank you.

https://www.longthorneguns.com/gunroom/innovation/



http://huntmag.eu/interesting-visit-by-the-icsi-to-longthorne-gun-makers/

 

[bruce moulds]

there is an issue that must be taken into account.
it is that NO barrel is ever straight internally.
this is because deep drilling works that way.
when fitting up a rifle for extreme accuracy this must be taken into account by doing 2 things.
firstly the chamber must be reamed as a tangent to the curve of the bore, which takes a lot of time setting up and measuring.
secondly the curve in the barrel is set up so that the muzzle points downward at its lowest point.
with the axis of the chamber parallel and on centre to the centre of the bore line, the bore interior at the muzzle will usually show quite a bit of runout as the barrel is turned on its threads in the receiver.
point of impact is definitely affected by this.
for some reason, the curve pointing downwards offers the most even barrel vibrations.
deep drilling 2 bores from the same piece of steel to have absolutely the same curve, and in the same direction would be about the same odds as being struck by lightning.
bruce.

 

[sambarhunter]

Did you not read the links above?

 

[bruce moulds]

yes I did, but what I said remains a fact for rifles.
I note that longthorne guns are shotguns, things which I know little about.
possibly they have different requirements to be accurate and zeroed, and other things I do not understand.
another thing to be wary of is marketing, until proven otherwise.
I note that they claim to make their bores parallel in order to avoid crossover.
even with a shotgun, the bores need to come in toward the muzzles to actually achieve parallel flight, because of what happens during recoil with 2 different axis and the same position of everything else.
history may well record me as a luddite, but I await double rifles to be successfully made this way.
bruce.

 

[sambarhunter]

Longthorne seem to have come up with the goods that the naysayers say cant be done.
I reiterate without argument that in todays day and age of the best manufacturing gear that is evolving weekly that I wouldn't put my name on the naysayers list.

 

[bruce moulds]

we will have to beg to differ and remain friends hopefully.
bruce.

 

[Ryan]

Longthorne seem to have come up with the goods that the naysayers say cant be done.
I reiterate without argument that in todays day and age of the best manufacturing gear that is evolving weekly that I wouldn't put my name on the naysayers list.

I've been reading this thread from the start, learning a great deal about a fascinating subject.

I agree that where there is a will there is a way and technology is always advancing. That said, Longthorne has advanced shotguns not rifles with this technology. Why? Will you be contacting Longthorne to find that out? Their answer would be interesting to a lot of us.

 

[rookhawk]

Longthorne seem to have come up with the goods that the naysayers say cant be done.
I reiterate without argument that in todays day and age of the best manufacturing gear that is evolving weekly that I wouldn't put my name on the naysayers list.

I think the practicality of doing this for shot in a gun is much more than for bullets in a rifle.

I tried to imagine how it could be done, and came to this:

For a double rifle, it would need to look like a tuning fork, meaning the last several inches would need to be unjoined, allowing for a regulation wedge to move the barrels. At that point, it hasn’t saved you much time or cost in manufacturing, nor would the result be “better”.