Back Action Locks

[Codger Craig Wilcox]

When did the back action locks first come about, and by who? I've got my meat hook hands on a boxful of them, and am actually trying to replicate a .50 cal Deringer pistol with one.
They are kind of neat, and quite a bit different from the standard lock. I am thinking that they must have come about following the invention of the percussion cap. While probably possible to have a flintlock version, it would really look awkward, and difficult to manufacture.
For me, it was a chore to figure out just where the trigger went so that the bar could reach up and trip the sear. Things are not always as they seem, are they?
For the Deringer, I am using a chunk of English walnut that was actually harvested in Armenia. The coloring is splendid, but Oh My! that piece of wood is hard and dense! Seems I am constantly sharpening my cutting tools. Have a couple other ML's going in the same wood, a nice Jaeger, but not looking forward to fighting that - got the barrel in before my arms fell off!
So, back-action locks - pro/com. advantages/disadvantages, history of.... Thanks in advance! Craigo

 

[rich pierce]

Back action locks were developed first as the back half of the flintlock swivel breech mechanism. The pan, frizzen, and frizzen spring part, or front of a flintlock, was affixed to each of the swiveling barrels. The back action part was comprised of the internals plus the cock. This worked perfectly for adaptation to cap locks. I do not know if back action percussion locks predate 1840 by very much. They are considered fast but the L&R version does not impress me compared to ones I have on an English shotgun. The mainspring seems wimpy and can blow back to half cock from the cap flash.

 

[Feltwad]

Lovels patent back action lock came out in the 1834-35 it was claimed to be a faster lock and some were fitted with a fly . Their biggest fault was they took up most of the wood in the wrist leaving this the weakest part of the gun . The patent gun maker James Rowntree patent a back action lock between 1810-14 which he fitted to a patch lock
Feltwad

 

[Codger Craig Wilcox]

Knew my ALR friends would have the answer! I had been pondering how to use one as a flintlock, and the swivel gun thing really makes sense, keep the frizzen and pan separate. I guess that could still be done with one of these locks I've accumulated.
Quite honestly, I don't know if it would be faster than a regular percussion lock or not, and to me the difference would truly be immaterial. I CAN tell, and appreciate, that percussion locks are generally faster than flint, but that is perhaps because I can recognize the pan flash before the gun fires.
They (BA locks) do seem to be easier to inlet, although fitting them in so the cock clears the fence seems to be more difficult. I think that is a matter of experience, however. And it will be fun to use a piece of fine silver over the wood below the nipple.
Thanks for the answers, Rick and Feltwad.

 

[Notchy Bob]

Many years ago, Dixie Gun Works listed a 4 gauge smoothbore "Elephant Gun," which they claimed was actually traded to native hunters in Africa. I distinctly remember this gun was made in Belgium and had a two-piece flint lock. The primary part of the lock, including the cock, was a back-action design. The pan, frizzen, and feather spring were on a separate, smaller plate. I recall that Dixie also listed the lock by itself. I have no idea why the builder or designer of this gun elected to use a two-piece, back-action flint lock on a single-barreled gun. @rich pierce made a good point in that the back action design is ideal for a flintlock swivel-breech, but I don't see any advantage on a single-barreled gun with a solid, one-piece stock.

I have read that back action locks were "faster" than conventional front action or "bar" locks, but I have never seen any data from objective testing to support the claim, and I don't really understand why or how there could possibly be a significant difference. I would agree with @Feltwad in that the inlet for a back-action lock would remove wood from and thereby reduce the strength of the wrist of a long gun, but on the other hand, a back-action lock would reduce the likelihood of interference with the ramrod hole. Maybe sort of a trade off... Leave some wood here, remove some there.

If you Google percussion plains rifle or percussion buffalo rifle, you'll find a lot of images online showing rifles with back-action percussion locks. They were apparently quite popular in the mid-19th century, but today, Pedersoli's Tryon rifle is the only mass-produced replica gun I know of that uses one.

Interesting discussion. Thanks for introducing the topic!

Notchy Bob

 

[Codger Craig Wilcox]

Thanks, Notchy Bob. I do recall Dixie's "Elephant Gun", if only for the reason that I feel a person would have to be at least half-crazy at attempting to kill an elephant with a firearm that had one, and only one, shot. Reloading a ML during an elephant charge means someone beside the elephant is going to get killed.
I do like the idea of the swivel breech using a back action lock, with individual frizzens and pans for the barrels. That would seem to be an idea that would hasten the availability of rapid second shot.
I may resort to using dynamite to excavate the lock mortise on the pistol and the Jaeger rifle - that "Royal Walnut" is TOUGH!