Flint pistol - Nationality?

[corrado26]

Ok, my mistake, screwable is the expression.

Here is a pistol of my collection made by Andreas Erttel gunmaker to the court of Saxony with a rifled barrel. The twisted grooves go down the barrel until the powder chamber and as you can see the thickness of the barrel's wall is not that much though there is a muzzle ring that increases the thickness remarkably.
corrado26