Intercepting sears, generally found on sidelock British guns, were also used on better quality boxlocks as well (I have one, for example, that is on a boxlock Lancaster double rifle--it is Holland and Holland pattern). To the best of my knowledge, there were two patterns used, the Holland and Holland pattern that used two parallel sears, while the other pattern by Purdey, used a pivoting arm. Were there any other patterns used, especially on boxlocks, and if so, where can I see pictures of them to study functioning? With the Holland and Holland pattern, I can't understand how they work, unless it is simply that the two parallel sears are far less likely to fall out of notch in tumbler, compared to only one sear possibly falling out, because the ones I have seen have no means to prevent the double sears from falling out of notch, bent---they are made same as single sear gun, but have the double parallel sears. Where can I see pictures or drawings of the Purdey pattern, especially in enough detail to understand and study how they function?
To the best of my knowledge, no MODERN double rifle maker, from Germany, Spain, Belgium, France, Italy, offer intercepting sears standard, but at least one French double rifle maker does offers them as an option at more cost. Anybody know of any of these countries modern double rifle makers offering them? If you are an intercepting sear expert, please comment on your opinion of the reliability of the H & H pattern, and on the Purdey pattern, and on any other patterns you are familiar with.