Large siler.
Ditto!
I consider the large siler to be a fairly small lock. I have used it on pistols ......
To be honest this is a "your mileage may vary" thing but its a very interesting topic that can be discussed.
So I will play "Devil's advocate" here.
I don't build fowlers and don't like really big locks simply for the accuracy thing. A large siler frizzen, for example, produces a lot of shock when it springs open. I have a pair of them on a swivel breech. Will not make that mistake again.
I have a Dale Johnson large Siler on a 18 pound rifle and it does not shock the rifle much. I will put the other Johnson lock I have on a much lighter rifle without fear and if fits the design of the original rifle well.
But its still a great lock. But in a pistol the shock of the frizzen opening will move the gun and this is not good for accuracy. This is the reason I like to use the L&R 1700 for pistols where its correct. Firing the lock does not jar a pistol.
But for smaller rifles the small siler is a great choice and can be used with barrels to 1 1/8" without causing architectural problems.
Its easier to make a nice rifle with a slightly smaller lock than one that is too big. Not saying that a large lock is wrong. Lots of original guns have large locks on them. But the larger the lock the weaker the stock if its slim.
I once made a 1/2 stock rifle with the Large L&R waterproof lock. It was a great lock with some minor tuning. But with a 1" barrel and a 3/8 rod hole and the stock cut to make the proper clearance, about 1/8" covering the rod the lock was just about too big. So much so that I have never used another one.
A small siler with a .900 breech barrel will make a very nice rifle or pistol 1 3/8" deep at the front TG extension and still leave some wood around the lock.
Thin lock mortices can cause trouble with pistols cracking around the lock under recoil especially if a single lock bolt is used.
The rifle that goes with this pistol, they belong to my son. Has a 7/8 barrel and a large siler and it looks fine too.
Dan