Will this launcher design work? Answered

Concept - A hybrid-launcher (combustion and pneumatics) with interchangeable barrels for various projectile types

So the design is pretty simple, in the back of the gun launcher thing (we’ll call it ‘the weapon’ for now) will be a propellant chamber measuring 2.5” wide and 1.5’ long.

On one end of the propellant chamber will be an unscrewable coupler. On the other end, a 2.5” ball valve. Attached to the ball valve will be the female end of a 2.5” coupler (without cap)

From here will be the interchangeable barrels, which are simple. The barrels would consist of the male end of the 2.5” coupler and a 2.5” width converter, converting the width from 2.5" to various different sizes for the different projectile sizes (this would have to be one piece for durability, idk if such a piece exists, I hope it does, if not, i can make one) the barrel itself would measure 3’ in length

A Shrater valve (bike tire valve) will be installed on the propellant chamber (for pneumatic power). A bike pump would be mounted on the weapon (like a shotgun kinda) An ignitor will be installed on the back of the chamber, mounted on the unscrewable coupler.