The Cameron-Yaggi conversion was an experimental American trench rifle that was never put into service. However, this one example has survived, and today we are going to put a few rounds through it.
The literature says that recoil is mild, and the periscope actually moves away form the shooter when fired. This is not the case. The periscope goes right back into the shooter’s eye, because it has a very short eye relief. The periscope also provides a very narrow field of view, and I expect it would have been very difficult to actually use this contraption effectively in the fighting of World War One. That said, the device is sturdy and easy to use, unlike most of the other trench rifle adaptations I have seen.