Goofs

The Thompson sub machine gun drum magazine has a maximum capacity of 100 rounds. Al was firing many more rounds than that without reloading. This might have been a dream sequence scene.

When Al was firing the gold plated Thompson SMG there are several times when the bolt is forward then he fires again without reloading. When firing a full-auto Tommygun you must pull the bolt back then pull the trigger. The bolt flies forward grabbing the next round in the magazine to fire. When you have fired the last round the bolt slides forward and does not return to the rear position because a round has not fired to cause the bolt to slide back, it stays forward. That is seen several times and Al does not reload.

Several mispronounced Italian words in Capone's outbursts.

While Gino is stabbing Johnny multiples times in the neck/shoulder, Johnny continues to move (simulating being stabbed) a few seconds after Gino has stopped stabbing.

The fishing boat used by Al and Johnny sported 50 star U.S. flag. Should've been 48 stars.

The use of Louis Armstrong's Blueberry Hill is inaccurate. Capone died in 1947. Armstrong recorded the song in 1949. It reached 29th on the a Billboard chart.