Since it seems gun control is hard to legislate for in some countries, today’s invention is a way to allow people to own guns for home defence which have severely limited range.
A conventional semi-automatic has a number of extra ports created in its slide. Its barrel too would have perforations around its circumference, corresponding to these ports.
When the trigger is pulled, the gunpowder ignites and the slide moves backwards as normal. Much of the energy in the cartridge is however lost as the ignited gas vents through the barrel and ports.
This greatly reduces the muzzle velocity, allowing a homeowner still to apply lethal force but with greatly reduced danger to bystanders from stray, long range shots and ricochets.
The ports and vents could be positioned circumferentially and sized so as to react accurately against the up-kick and torque which firing such a weapon generates.
The effect would therefore be to improve accuracy significantly at close range.