Given the recent threads about the 12/20 and seeing as I had one in pieces, I thought it might interest some to see the guts of the Baker patent lockwork, as used in the Lancaster 12/20 among others.
This is a 12b SLE retailed by J Blanch & Sons, an unwanted inheritance that came to me in a rather poor condition. Some 30 hours later and several 100's in specialists, it is coming together nicely and will be my go-to game gun for the next few years.
The patent uses a 'carrier' for the mainspring which, like the famous Purdey/Beasley action, cocks the tumbler by the force applied by a spring. In the Baker patent, this is a separate spring that you can see at the top of the disassembled lock parts, acting through the main spring.This makes it a member of a very rare and exotic group of gun actions that are described as 'spring cocked'.
Another similarity to the Purdey is that when the gun is open or dissembled, the main spring is not under compression so there is no need to 'let down' the locks for storage. The main spring is only put under tension when the gun is closed, by way of the lever (centre right), pivoting in the floor of the action, forced down at the front by the barrel lumps and 'cramping' the mainspring carrier.
This gives the impression of the gun being a self opener but the opening force largely evaporates once one or both locks are fired, so it is not a true self opener, just an 'assisted opening' when un-fired.
As can be seen, the lockwork is actually a 'back-action' (mainspring behind the breech face) but the lock shape often leads people to assume a 'bar-action' (mainspring in front of the breech face).
The whole concept is wonderfully different from the normal lock work used by Holland Holland etc at the time and shows some real 'blue sky' thinking.
Interestingly, the ejector work is also on a similar patented design, sharing the feature of the springs remaining un-tensioned until that spring's lock is fired.
These beautiful guns were designed and largely built within the Birmingham guntrade which shows how misinformed the denigrators of the Birmingham trade are!
As a point of interest, it is often said that back action locks give poorer trigger pulls that bar actions.
When regulating the trigger pulls on this gun, I found it easy to achieve a delightfully crisp pull of the required poundage with no creep and a variance of only an once or two between tests.
Considering the blood I have sweated over some quality bar actions, give me a Baker back action any day!!
