The magazine is basically a flat cylinder, or a harmonica shaped magazine containing chambers, so the fired cases is extracted and reloaded when all chambers has been fired.
The sight could be a problem, but the idea with this gun is just a simple and small derringer, able to fire faster than a ordinary single action, so the sight isn't my biggest concern. But my idea wasn't to push the harmonica magazine upwards from the begging.
I thought it would be a great idea to create a design which could make a ordinary derringer, or basically any other single action (or maybe double action shotguns etc.) especially break action designs, speed loaded in a reliable and easy way. Otherwise the spent case has to be extracted and manually reloaded after each shot, which makes the fire rate slow..
The evolution of this gun started like this:
https://imgur.com/a/V7lGT
and i thought that a chamber that holds the whole rounds, would be a good idea, and i came up with this:
https://m.imgur.com/a/gavoh a harmonica like magazine which holds the chambers, chambers which is manually inserted into the main chamber of the barrel.
To extract the fired chamber and chamber a new into the barrel, you just have to push the harmonica magazine (H. Mag.) backwards so the chamber is realeased from the barrel, then aside so a new chamber can come inline the chamber of the barrel and bore, then just push the next chamber down the barrel and fire the gun. So you operate the magazine, instead of operating each small rounds.
The next evolution was this:
https://imgur.com/a/ka0zV a H. Mag. that just has to be slided alongside (or upwards) the barrels cut, without haveing to be pushed back and forward to realease and chamber the magazine into the barrel. This design made it possible to hold the H. Mag. in the grip, since the H. Mag. doesn't have to be manually operated, a spring in the end of the grip would work to operate the magazine.
Grooves/hooks hold the magazine inline when fired, and has to be manually released to chamber the next round, that hooks in place.
I thought it would be nice to just have to operate the hammer/firing pin and trigger, so i made this design:
https://imgur.com/a/YccoU (bad & primitive image because it evolved fast to the design below) which was made for a open bolt gun, where the bolt push the cartridge into the chamber, and fires it, and when the bolt is pushed back and the firing pin is cocked, a new round will travel up, ready to be fired.
I thought that it wouldn't be a great idea to rest the whole H.Mag. on a single cartridge, so i came up with this:
https://imgur.com/a/o9XNR https://imgur.com/a/GPrHE (the dimensions isn’t correct for .22, just made up basic mathematics)
But at this point i thought that it got to complicated, the barrel has to be customized in a very perfect way, and there could be issues with the bolt hitting the blocking pin below, and the blocking pin won't going in, falling out etc.
I came up with this:
https://imgur.com/a/19Z2W (ignore the dimensions)
With this design you have to manually pull the blocking pin out, and with a small pin like that, it could be hard to get a grip of it, for example.
So i came up with the slot/teeth design that this thread is about.
But gas leakage and the magazine operating faster than the gas leaving the chamber and bore, etc. could be big issues. And the barrel and magazine won't be that easy to make either.
Today, i made a new design, based on an old:
https://imgur.com/pg1zPhu
https://imgur.com/84z0Sjt
The chamber that holds the round within the chamber of the magazine, is movable.
It's the newest design, you have to manually push the block (which also chambers the round) fully inside the chamber of the magazine.
I think it will be easy to do and it will be fast to operate, and this design allows you to push the block in, instead of getting a grip of the block to pull it out, like the old design, and you won't have small blocking pins to keep in your hand or pocket, or picking up from the ground
https://imgur.com/a/xcQG5 (The dimensions isn't 100%, the visible chamber that blocks the magazine is to wide i guess, and there is no trigger either, the image shows the basics)
Easy safety:
https://imgur.com/a/HtDmN
With this design, you could make some kind of trigger that push the block if it's to small for your finger etc., it could also be made like this: which allows you to push it forward, and it also allows the handle to hold everything in place. It won't be any space that can accidentall move the block within the magazine when stored. The blockage will also block the magazine at bouth the left and right sides of the barrel cut, maybe makeing it more stable.
The whole design that i'm chasing here, with this gun, is something very reliable and easy to operate and handle, which is basically fool proof, in that way that it can't go wrong, just a basic single action gun that can be fired like a semi-auto.