To my way of thinking Purdey and Holland have very thick standing breeches on their double rifles for several of reasons including: (1) there is a need for the extra depth of the standing breech for the third fastner locking bolt to fit into for the the long travel it has to make to engage in the slot of the barrel extension, (2) in order to have much mass to try to prevent the movement of the breech away from the barrels during firing because they do not have a third fastner bolting system via a barrel extension that actually locks the the breech and barrels together such as WR and Rigby which will hold the barrel and breech together during firing---they have to depend on the draw/circle perfect fit and(3) you need a lot of action mass in order to get the weight of such a double rifle up to between 11 and 13 pounds in order to be able to tolerate the recoil and the standing breech is a good position to place extra mass that will aid in balancing the DR as well.
Double rifles without a "locking" third fastner (as the types WR and Rigby have for example) need more mass in other areas as well in order to keep the hinge pin from being pushed forward distorting the knuckle, especially in some of the magnum calibers where chamber pressure reaches 60,000 psi. Wider actions, and wider barrel lumps along with more mass in the knuckle and the perfect tight fitting of the draw of the rear lump against the circle has been methods used as heavy breeches alone will not keep the hinge pin (even though it is large diameter for a DR) in place very long with these kind of pressures if you do not have some way to keep all the force off the hinge pin. The draw fitting against the action circle when the action is closed should be of similar tight fit as the forward lugs of a rifle bolt fitting into the slots of the rifle barrel in a bolt action rifle when the bolt is turned downward and closed. very few craftsmen have this skill.
Stephen Howell
Last edited by bushveld; 02/20/23 06:04 PM.
