Goofs

When Liam Neeson's character offers to let Curtis look at the shotgun before pistol whipping him, the shotgun changes from a side-lock engraved shotgun to a plain box-lock.

After the character played by Liam Neeson retrieves his hunting gun on the back seat of the terrorists'car and sets to tracks Doireann the rear right door of the car behind him is seen opened with no reason.

Briefly dropping a shotgun cartridge into water would not cause it to misfire.

In the pub shoot out: both Finbar & one of the IRA terrorists use Beretta model SB, 92F type 9mm pistols. These semi automatic models were not made in 1974.

At 6 minutes in, when Finbar and the Garda are discussing the broken sign, two wind turbines can be seen on a hill in the distance on the right-hand side of the screen. The 1st wind turbine in Northern Ireland wasn't until around 1995. The film is set in 1974.

During the opening couple minutes a Triumph 2500S is seen driving along a street and parking, the Triumph 2500S wasn't produced until 1975 so didn't exist in 1974 when this film is set,

During the climactic gunfight, a Beretta 92FS is used by Conan and subsequently by Finbar. However, the Beretta 92FS was not introduced until 1988, while the film is set in 1974.