Since Frank Castle became The Punisher he has used a variety of weapons to kill the worst scumbags in existence. The one weapon iconic to Frank is his favorite side arm. The hand gun most associated with Punisher since his beginning is the Colt M1911. Until the mid 1980s. the US service pistol was the 45 ACP M199 pistol. Frank being a Vietnam vet was very familiar with this great gun, and he mentioned it over the years from his various books and even the special yearly Punisher Armory.
Pictured above are a variety of M1911 Colt that would be the type used by Frank. The top Colt is a stainless steel gun with features that make it easier to use in combat conditions and competition. The changes from a standard USGI model 1911 are meant to make it easier to use and manipulate faster. The second gun down is what the M191 Frank would have been using in the war, and early in his career. It is the M1911 made to the USGI specs., It has none of the later enhancements that come from years of refining the pistol for maximum efficiency and speed, The third pistol is a pure modern combat pistol with a rail on the frame to allow it to take a light or laser
If you are not familiar with weapons and wonder what the big deal is with this much respect pistol and its power,
The guns above are all real Colt 1911 pistols, There has been a great many of them made before and since the Punisher came along and they are as timeless and as classic as The Punisher is himself.