What is your favourite bit of airgun design engineering that is ingeniously simple?

[ccdjg]

After many years searching I have just managed to add a French MAS air pistol to my collection (central pistol here: http://i135.photobucket.com/albums/q...psinfk7kun.jpg )

After putting it through its paces l was struck by the beautiful simplicity of the pellet loading system. As the trigger guard cocking lever reaches the end of its stroke a peg in the end of the lever rides in a sloping notch in the barrel and pulls the barrel forward a short distance, which allows you to insert a pellet in the breech. Returning the cocking lever reverses the process and pushes the barrel firmly back into the breech seal. So with a bit of simple but ingenious engineering design the complications of a barrel hinge and a barrel catch are avoided and an infallible positive breech seal is achieved. This photo shows the cocking lever at full stroke: http://i135.photobucket.com/albums/q...pscbfksiwh.jpg

This set me thinking, what other additions or modifications have been made to traditional air gun designs, which are both highly effective yet ingeniously simple? Which ones could be classed as the cleverest and most cost effective?
One of my favourites is the breech closure that Frank Clarke invented for his range of Titan air pistols.
His first model Titan, usually referred to as the Mark 1, used the barrel-over-cylinder design, where the piston moved rearwards and the compressed air has to make a tight U-turn before it reaches the pellet in the breech. http://i135.photobucket.com/albums/q...psxp0a2zxk.jpg

The pistol design had several disadvantages: the cocking plunger had to be pulled forwards so making the use of a strong spring impractical; the plunger itself made the gun ungainly and you certainly couldn’t keep the pistol in your pocket; the breech seal was achieved by a bolt action, the barrel itself serving as the bolt. The last feature meant that you could never be sure that the front sight was vertical when the barrel was firmly locked against the breech washer. Not surprisingly the Mark 1 was not a great success and was soon replaced by the improved Mark 2 . And with a final refinement he produced the Titan series Marks 3-7.
What Frank Clarke did was pure engineering genius. He introduced a closure to the air cylinder that instead of being fixed, as in all air pistols made before or since, was rotatable. With this simple design change he was able to (a) provide a closure to the rear end of the compression cylinder; (b) provide a channel to direct the compressed air from the cylinder to the barrel; (c) provide ready access to the barrel for loading a pellet, followed by positive barrel sealing by a simple quarter turn of a breech block; (d) allow a cocking push rod concealed in the grip to be rotated until it was in direct contact with the piston head, when the piston could be pushed back into the cocked position, and the rod then rotated back into the grip. And all this was achieved with a simple breech block engineered from a single piece of steel. The following pics show the essential working of the breech block. http://i135.photobucket.com/albums/q...psdmsnrnwg.jpg

The manufacturing cost saving must have been dramatic, and the subsequent Marks 2 -7 Titan pistols based on this design were a great success. So although the Titans could never be regarded serious target weapons, they were sturdy and affordable plinkers, far ahead of the push-barrel pistols available at the time.
Although this is my favourite bit of air gun engineering design, there must be many other examples of ingenious air gun inventions (simple ones I mean) out there that have impressed you. What is your favourite one?

[jassi]

I like the action of Hammerli Master pistols.
When you cock the pistol a cylinder rises from the barrel to accept the pellet . When loaded, you push the cylinder down and its ready to shoot.

[buttloaves]

I like the action of Hammerli Master pistols.
When you cock the pistol a cylinder rises from the barrel to accept the pellet . When loaded, you push the cylinder down and its ready to shoot.

Sounds a bit like a HW57 rifle.

[buttloaves]

I think the spring loaded magazines used by theoben, benjamin etc are a very sipmle yet clever idea, when you think of all the mechanics they do away with, the indexing system on my HW100 is quite simple really but nothing compared to plastic ones above mentioned. I wonder who thought of it first.

[milek]

FWB sliding rearsight.

[Mark D]

Hy Score single shot loading mechanism. Quick,simple and very effective

Not like the multi shot mag they also came up with

[p.sharp]

Fwb swivel / cocking arm axis pin combination. Simple yet effective & still not been copied, AFAIK.

[RustyBuzz]

The record trigger.

Cheap as chips, just lots of pressed tin, but very effective - brilliant piece of design

[thisisdonald]

I was lucky enough to have ValeBoy from here visit me with a bootful of old classics the breech arrangement on his Greener was fantastic and similar to your MAS pistol. when the barrel was returned it was pulled into place making an effective seal.

for total simplicity of design, look no further than the humble webley break barrel breech seal

[I. J.]

The record trigger.

Cheap as chips, just lots of pressed tin, but very effective - brilliant piece of design

50+ year old and STILL a target for its modern day competitors to copy.

I also like the HW100 single shot tray adaptor. O.K. - maybe not classic yet.

[Rob M]

Another vote here for the Hy-Score breech. Simple, few moving parts, no seals that wear out or need replacement. Easy and quick to use when you get the knack too.

[BSFNUT]

Breech Lock on my HW55T, much better than the one on my HW35 Vixen

[pennineway.fswo]

Wembley Service Mk2. barrel lock-up/breech seal design.

[ccdjg]

Some good suggestions, but I am surprised, given the number of BSA collectors out there that no one has mentioned the Lincoln Jeffries tap loading system. Just one moving part meant that there was no longer any need for a hinged barrel or breech seal, and loading the pellet was simple and safe. Wobbly barrels and replacement seal washers became a thing of the past, and there was no need for a safety catch. With hindsight an obvious development but it took a very clever man to think of it first.

[xbow]

FWB trigger.