The 4 Shot or Wide Shot is a recurring weapon from the 1940 series. While it was originally represented by a POW icon in the first game, it later got represented by a four-bullets icon.
On it's original appearance in 1942, where it was the only real power-up available other than the Side Fighter, the 4 Shot added two extra bullets to the player's shots, making it wider. The weapon returned in 19XX: The War Against Destiny, where it serves a similar purpose, making the frontal shots wider and thus adding to the firepower. It is the preferred weapon of the Lockheed P-38 Lightning, and when maxed out with it will shoot even wider shots, up to 6 bullets total.
In 1944: The Loop Master, the 4 Shot is the player's default weapon and the only weapon available, but by picking up Shot power up icons carried by yellow enemy formations it will add more bullets to the spray, making it wider and practically doubling the firepower when maxed out. The weapon returns again in 1942: Joint Strike, where it works much like it did in 19XX.