in "The Gun & Its Development" W W Greene described fitting one of his guns so it could hold a non elastic strip between the breech & barrels. He removed the connection between the top lever & cross bolt & built a bolt with extended length so it could be inserted or removed by hand. With normal loads he reported the trip remained intact with or without the crossbolt. As loads were increased the strip began to be broken when the cross bolt was removed, but remained intact with the bolt in place. In fact he stated he went to some extremely excessive loads but could not break the strip with the cross bolt in place.
It would indeed be interesting if someone who had the facilities to do it wold take a long recoil operated shotgun & remove the bolt which locks the breech-bolt & barrel together.
Then set up & fire it while filming with the high speed photography. The barrel would of course have forces working both ways on it. Friction from the shot & wads would be trying to push it forward, while friction of the case would be pushing backwards. Would be interesting for sure to know which force won
