A turn off pistol

[fernando]

Hi Simon,
Thanks for your input

Originally Posted by gbxfb

Hi Fernando,

If you look at the breach of your pistol it will probably be slightly concave so as to hold an oversized ball, say 4 to 5 thou more than the nominal bore size, on top of the central chamber, if the chamber is just overfilled and the ball is sized correctly as the barrel is screwed home it should just nip the ball with the lip of the bore and hold it tight. This will give the 'forced' shot that Fernando K refers. There is a danger of leaving an air gap with this loading method if the ball is undersized or the chamber under filled.
I think that the 21 markings on Fernando K's pistol may be a reference to it's imperial bore size at 21 to the lb or about 15mm. Nice pistol by the way!

Best regards,
Simon.

I knew what the forced shot is about; even thought that all turn off barrels were so made for such purpose.
The problem is to estimate the concavity dimension of the breech chamber and compare it with the barrel bore, concluding whether the bullet to be loaded is oversized or not ... specialy when dealing with the rusticity of materials; the breech of my example is visibly concave but also not concentric. I have tried to phisicaly check the differences with some balls (spheres) i have, but i miss the ones that could do the job .

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