Ferguson breech threads.

[Matt Maier]

Question about the Ferguson breech threads. Are they more of a square or a V thread form? I can't see very much detail in this picture but it looks very similar to a square or acme thread.

 

[dd832]

Here's the breech, and 2 photos of the plug and a diagram of the double thread. I believe the plug is 10 threads per inch (and a double thread) so the breech opens quicker.




Mike

 

[Metalshaper]

actually, I believe it is one thread per inch, 10 starts or lead/pitch....

of course I could be wrong??

Respect Always
Metalshaper/Jonathan

 

[Matt Maier]

actually, I believe it is one thread per inch, 10 starts or lead/pitch....

of course I could be wrong??

Respect Always
Metalshaper/Jonathan

I had heard it was 11 TPI, 11 starts. But yes, each thread had its own lead, which is what allowed the breech to be opened with a single rotation of the trigger guard.

 

[Metalshaper]

I had heard it was 11 TPI, 11 starts. But yes, each thread had its own lead, which is what allowed the breech to be opened with a single rotation of the trigger guard.

Think the originals were 11, but my mind "thinks" I remember the replicas being made with a 1 pitch 10 start thread?
but then again its been said I have lost my mind!!

Respect Always
Metalshaper/Jonathan

 

[Matt Maier]

I think we're all a little crazy, but that isn't a bad thing.

 

[Metalshaper]

anyway I look at it, my lil lathe won't cut that pitch unless I do some fancy gear switching out on the banjo..
and then I'd probably have to hand crank it?? cuz I'm not sure at it's slowest speed I could keep up with the carriage
traveling that fast ..

Respect Always
Metalshaper/Jonathan

 

[Matt Maier]

I know my lathe won't cut one TPI, and I don't know what lathe would, unless I could program it on a CNC. CNC machines are very expensive though.

 

[Metalshaper]

I had worked up a gear set to try it on my lathe, but haven't had the time to cut gears or get someone with a 3D printer
to make a set .. and the lead screw one is gonna end up a special made and have only one specific purpose...

 

[Matt Maier]

I might save up for an old Pratt and Whitney. I don't have knowledge of designing gears or how to calculate gear ratios.

 

[Rudyard]

The Late Ernest Cowan made up five or so Fergusson's The Breach of one bore Mr Hoyts stamp perhaps these plugs could be had from Hoyts.?. The breach end shown looks like they are produced by some firm and others have made them before CNC came in .Its a quantity issue no doubt . It would be of interest to many but how many is a question and aside of the novelty what real use would a plethora of Fergusson's be anyway ? .
Though my guess is few serious gun makers could resist making one up .
I made a 'Turn Off' flint BL rifle used it hunting concluded while powerful its slowness in reloading was against it and the muzzle loader a better option . I once shot 13 shots inside 20 minets allowed in the completion for' breech loaders' was inside the time but outside the placings against cartridge rifles , But the ideal conditions of a range are not so easily duplicated in the bush / field .
Conclusion ? ' Never catch on' still intrigues me anyway.
Rudyard

 

[Matt Maier]

For me, its historical interest. The Ferguson is unusual and represents a concept that was ahead of its time. I'd never want to make them in quantity, just one for myself.