Marraki,

What is an intercepting safety? Is this the same as what we call stalking safeties on hammer guns? A slide that would prevent a hammer from falling - often on the muzzle side of the hammer but sometimes a slide to the rear of the hammer which also prevents the hammer from falling.

Armbar,

On a sidelock there is no externally visible sign. On a boxlock there is - often, alway, sometimes? - an extra screw to the rear of the fences.

Might want to look at www.hallowell.com . They have a photo of a bar action sidelock with intercepting sears that you can see (unlike their photo of a back action lock where they aren't so obvious) and I think a photo of the extra screw location and a written description of them as well in the definitions section.

Mickey,

That would be E Type!

Mehul,

Mickey is right, they are typically only present on higher grade boxlocks and sidelocks. But many higher grade boxlocks don't have them.

JPK