DRJack;

No offense taken and we will disagree upon using the circle form against the draw or a flat straight surface. Your thoughts as well as your Italian colleague on the superiority of the circle to a flat are well taken. I like the flat replaceable insert better, for several more reasons that could be discussed in the future.

However, your hypothesis that the third bite on a English built double rifle the quality of a Purdey, Holland or Boss just holds the barrels down, is just that--a hypothesis. (Rifles require more than shotguns--which can get by with a poorly fitted draw and circle.) The assertion I made is backed with the experience of trained DR makers and physical evidence. I will quote here from pages 17 and 18 of Vic Venters "GUN CRAFT" c. 2010:

" .....When jointing a double rifle the equation changes dramatically. Here strength becomes paramount: The breech pressure generated by a .375 H&H Magnum average 62,000psi; the typical service pressures in a 12-bore game gun, by contrast, are only around 9,000 psi (and often lower). 'To allow the hinge pin to bear the stresses delivered by big-bore rifle ammunition is to court disaster,'said Turner (Robert Turner, gun and rifle maker). 'The hinge pin can actually be pushed forward, bulging the knuckle. Or, the rear lump can bend or crack, or the locking bolt can shear. Sometimes it's a combination....'..."

"The (DR) jointer's solution is to remove virtually all the load-up from the hinge pin when the rifle is fired (relegating the pin to solely a hinge pin for opening the barrels). 'When jointing rifles, it is essential that the draw has full bearing on the circle.' said Tandy (Richard Tandy, actioner for W.W. Greener--of the cross bolt fame).

As I stated in my original post, very few people know about jointing English design DR's ourside of trained double riflemakers. So your assumption is not than unusual.

I was happy to see Vic interview jointers and put the facts into print. I will review some of my other books and see what else if find.

Best Regards;

Transvaal.