There were a lot of English gunmakers experimenting with breech loaders before Ferguson. My understanding is that Ferguson's unique contribution was the design of the threads. From what I have read, earlier variations were made mainly as high-end sporitng guns, but apparently they were prone to fouling clogging the threads if they were used heavily, as in a military scenario. Ferguson's thread design allowed the gun to be fired many more times with less fouling, reducing the problems with jamming up with fouling.
Richard Chubb used to have a fantastic, pristine condition sporting rifle by Newton with a threaded breech loading mechanism - looked to be maybe 1760s-1770s. He brought it to Noblesville and Friendship for about 4 or 5 years in a row. It probably sold long ago. Made really slender like a fowler, but rifled, and just the sleekest looking thing you have ever seen. Wish I had gotten some pictures of it. As I recall, the threads were much finer and tighter than on the Ferguson - perhaps it was one of those prone to fouling(?)
The Dutch rifle in the second link is very cool too. Neal and Back show a John Harman fowler with a similar break open breech loading mechanism and back action lock, ca: 1730 (the frizzen, pan, and cartridges were integral assemblies - you would pre-load the cartridge assembly and drop it into place, snap shut the breech and you were ready to go!). Never heard any reports of how well these worked though.
Guy
