New (?) action

So I was thinking hard of how to improve upon currently popular actions (bolt, pump, break, lever, whatever) on some level. Here is my approximate line of thought:

The firearms of greatest use to me in dealing with my usual challenges are carbine length, light weight, but hard hitting. Why? Because my typical hunting environment is on or around my farm, where vegetation is dense, terrain is rugged, distances are short but lethality should be high - some varmints can be dangerous, and I might be in a hurry to kill them before they kill more of my livestock, or they run away to kill my livestock another day.

Paradoxically, I'm fairly open to single shot guns because I rarely get a second shot at shy, mobile creatures in dense vegetation. Semi-automatics aren't completely out of the picture, but in my experience they're more of a pain to disassemble, clean and otherwise maintain, and just pouring more lead at a coyote's tail rarely makes it deader.

How do you fit the most punch in the shortest, lightest gun? Bullpup construction, and a long barrel length as a percentage of total length.

I don't care for break action in general, but I do like the overall philosophy behind the Thompson/Center single shots, so my line of thinking led me to consider how I'd make a bullpup single shot which is not a break action.

Bullpup and bolt action rarely go together well, for a number of reasons largely related to the motion of the bolt and the position of the shooter's shoulder. Bullpup and lever action have the same problem.

Bullpup and falling block? Now we're starting to get somewhere, but how about this:

A bullpup pump action single shot. Slide the pump back, and the action unlocks, then the barrel moves forward (along with sights which are fixed to the barrel).

Insert a cartridge into the chamber's breech, in the back of the barrel, slide the pump forward. The barrel slides back, the action locks, the lock cocks. Pull the trigger. Bang.

Slide the pump back, and the action unlocks. The brass remains behind in extractor claws, and flips up (or even down - any direction is possible) with a released spring just as in most bolt actions, while the barrel slides forward again.

With an action locking shut by moving blocks, as in a Winchester 1892 action, it can be as strong as any action on the market. With the join between the (immobile) boltface and the back of the chamber/barrel shrouded by a heavy layer of steel which also locks the barrel into a highly consistent position, it should also be a very safe action.

Replacing a barrel as per Thompson/Center design? Easy. Slide the barrel forward, maybe flip a tab or other release, lift it out, put in the new one - done!

Why this might be an improvement on, if nothing else, break action single shots:

• Smaller platform for a given barrel length
• The action can be cycled and recharged while keeping the weapon aimed downrange
• Barrel swaps can be even simpler and faster
• Positive, multi-point locking can ensure very reliable point of aim

So. I find it hard to believe that I outsmarted firearms designers. Where did I go wrong?