Swiss-born British gunmaker Durs Egg built a number of breech-loading flintlocks using the system invented by clockmaker Giuseppe Crespi.
As detailed in the above by Matt of The Armourer’s Bench, the early breech loader had a lot going on including an action that pivoted up 90-degrees to load and a huge bayonet that looks like a fireplace poker. The gun he has is from a small lot of trials rifles built in 1785 for testing with various light dragoon regiments, though there isn’t much “light” about it.
The action is very similar to the obscure pillar-breech Kammerlader rifles later adopted in Scandinavia, only predating them by about 60 years or so, making the Crespi/Egg a very interesting footnote to bring up the next time gun nerds are present.
You can thank us later.