Home Forums Hunting & Shooting Ask The Gunwriters Bore Diameter and recoil: any relationship?

The middle of a Venturi tube is narrowed, causing acceleration. This is essentially what necking down a certain cartridge does, the reason that (everything else being equal, which admittedly it rarely is) smaller-bored rounds on a given case tend to create higher muzzle pressure.

The far end of a Venturi tube is of larger diameter. The differential in velocity between the two diameters creates a pressure differential that's a measure of flow. The "venturi effect" is commonly used when talking about accelerated flow of gas or fluid through a smaller tube.

It would seem to me that if a given sized case were fired into a smaller barrel that the pressure would be higher
all down the barrel not at the muzzle alone. In a venturi increase of velocity ( with constant mass flow)
results in a pressure reduction (as a result of conservation of energy. I think you are confusing a venturi with
a nozzle.
Good luck1