Simplicity is a perennial goal for engineers and gunmakers (who are engineers of sorts). In gun actions, simplicity translates into fewer parts, greater strength, longevity and reliability. Problem is, simplicity also means economy that inevitably attracts makers who build guns down to a price. Therefore simple has become synonymous with cheap.
But not always. The lock pictured here is from a James Lang built in 1888. The photograph is posted with the kind permission of the owner who goes by the name RARiddell on the Internet.
It shows a simple sidelock.
The simplicity is obvious. There is only one spring powering both the tumbler (hammer) and sear. With few parts there are few pins, the usual sidelock has at least seven to impress the pin counters.
A quick parts count shows a tumbler, sear, sear axle, bridle and three pins. Compared to the London sidelock it is missing the sear spring and axle, the intercepting safety and its spring and axles, and naturally the more extensive bridle with the additional pins.
Simplicity breeds contempt, and some were quick to call this a «low grade» gun because it lacks the complexities of the London type. But is it low grade?
Judging by the photo, the metal finish is equal to most London sidelocks. The fitting of parts seems up to the usual English standards of the period (1888). A closer look at the lock geometry shows that the sear bent on the tumbler has the more acute angle found on boxlocks. Presumably this was done to offset the absence of intercepting safeties. The sear-tumbler enegagment on the London sidelock employs a right angle, to give crisper trigger pulls. But that angle makes an accidental discharge more likely hence the need for intercepting safeties.
The more acute sear bent angle gives a more secure engagement between tumbler and sear. It also brings about a spongy trigger feel, according to those that claim to be able to tell the difference.
The single main spring has roller bearings at the tumbler end. The sear end has been placed near the sear axle giving a great mechanical advantage to the trigger finger. The protrusion that engages the cocking lever seems to be filed to fit the bridle curve.
All the above point to a well thought out and well finished, albeit simple, lock. It is probable that the average user would never know of the sear geometry and could never tell the difference judging by trigger pull alone. Low grade or not, this is a good lock.
Now let us look at another brilliantly simple gun, also English, that was built down to a price.
The BSA Single XII has a lock designed by the inventive William Baker. The man who invented, among other things, the Baker ejector. Baker had a knack for simplifying actions, making springs do maultiple duties.
The single coil spring in the Single XII powers the tumbler, the sear via an elbow. It also, via a two pronged spring guide, gives positive rebound action. A safety bent on the hammer prevents discharge unless the trigger is pulled. It is a brilliantly simple, effective and durable design.
But look at the finish! The parts are cut from flat stock, they could have been polished on a reciprocating lead drum for next to nothing. The maker preferred nothing. The action parts were placed in the gun with all the machining and filing marks intact.
The BSA Single XII is a case where simplicity was undervalued. The cheap finish betrays the brilliance of the action. It borders on nasty. Thankfully the parts are thick enough for polishing by the discerning owner.
The fate of simple actions tends to go more towards the Single XII than the Lang route. Shotguns such as the simple sidelock Slavia model 46, the various Anson Deeley clones, almost all single shots, abuse simplicity and give it bad name. The James Lang of the opening pic is a refreshing exception.