Warning: This article contains some themes of an adult nature that may not be suitable for younger audiences.
Blockbuster war films and TV shows are designed to shock and entertain viewers and would be quite boring if they were exact replicas of military skills, drills and tactics - but where should they draw the line when it comes to keeping the portrayal of the Armed Forces realistic?
While some artistic licence might be necessary to create the dramatic effects that make feature films more engaging for audiences, as fictional drama is not intended to be a factual documentary, there are still some creative decisions over scenes, props, portrayals of procedures and the like that leave well-informed viewers aghast.
So what are some of the major military gaffes that appear in films and why are they made?
The 'never-ending Hollywood magazine'
This is one that you perhaps do not need a military background to get annoyed by - the ammunition magazine that never needs reloading.
According to one military adviser, shots of actors reloading weapons on set are often filmed but are actually cut in the editing stage in favour of action shots.
The advice here to actors would be to reload while engaging in dialogue where the clips are more likely to be kept in.
'Band of Brothers', '1917' and 'John Wick' are good examples of ammunition awareness and incorporating some style into reloading shots.
Budget has a huge part to play and 'Band of Brothers' is a great example of how a big budget makes a difference to authenticity.
Hundreds of authentic Second World Word era weapons were bought specifically for the production, along with thousands of original and made-to-order uniforms.
The military adviser on set was a former US Marine and Vietnam veteran (he also played the role of Colonel Robert Sink), and the actors had to undergo lengthy military boot camp and weapons training.
This level of investment helped ensure its epic success.
Video: YouTube/Bad Lads Army
Military culture and how military personnel relate to each other
This is a tough one for the film and TV industry as the producer may be keen to get the technical details (weapons, uniform, location and so on) right but want to keep creative freedom over the interaction and dialogue which does not always make for great entertainment.
One irritation for veterans is when a Sergeant in the British Army is referred to as 'Sarge'.
This is used in the Police but not the British Army.
One explanation for mistakes such as these is when an American adviser works on a film with British military or vice versa.
Saluting and berets
A major annoyance for many viewers is on-screen saluting and badly-shaped berets.
There are some truly terrible examples out there (Steven Seagal – 'Under Siege') and while it’s perhaps understandable given that actors do not undergo the level of basic training that the military does, a lack of understanding over saluting rules and etiquette is an easy one to avoid.
This includes saluting indoors and/or when not wearing a beret (if not reporting to a superior officer), junior soldiers saluting their equivalent ranks or senior officers saluting a lower rank first.
There are many examples out there and 'The Hurt Locker' shows Colonel Cambridge with two US flashes, one on each arm, the wrong camouflage for the time period, soldiers not wearing Personal Protective Equipment (PPE) and for the eagle-eyed viewer, an Xbox 360 and a game, neither of which had been released when the film was set.
The military adviser was pulled from production over concerns about script content and may explain why there were so many technical and tactical errors in 'The Hurt Locker'.
Sometimes the wardrobe department or costume designers make decisions without the benefit of the military adviser (who is working on the weapons) or will choose a uniform they think looks better.
Cost can be a big factor if they are hiring in uniform and they haven’t got the right one. Big budget films should be able to fund the additional costs but smaller budget films may struggle here.
This can include medals on-screen for wars that had not yet occurred ('Hacksaw Ridge') or wearing medal boards on camouflage uniforms ('Flesh Wounds').
It can be hard to get hold of specific medals but with so much information on the internet available this is one that anyone with a bit of common sense can check.
One of the biggest Hollywood mistruths is perhaps that of the film 'U-571' which credited America with decoding the Nazi Enigma machine in 1941 despite the USA not even having joined the war effort at the time.
The UK's then Prime Minister Tony Blair publicly denounced the film as "an affront to British sailors".
Some smaller scale 'mistakes' like soldiers taking their helmets off and not wearing eye protection on set are included to ensure actors can be identified but it's difficult to justify errors like 'U-571'.
'Over and out' is a classic line that Hollywood often gets wrong.
It should be one or the other but never both.
'Over' means that the person has finished speaking and is awaiting a response.
'Out' means the transmission is finished.
Using real names over the airwaves ('Navy Seals') is also incorrect.
Most directors in modern films like to use real weapons that have been modified to shoot blank ammunition because it maintains realism but they are still dangerous and expensive to use and so a mixture of real, replica and stunt guns are used.
There are a few reasons why directors may use the 'wrong' or different types of weapons.
Sometimes it can be difficult for them to get the correct licenses (and some actors aren't legally allowed to use real weapons) and some types of weapons just don't work very well when used with blanks.
For example, the Glock is a reliable weapon with real ammunition but not with blanks whereas the Beretta is a lot less likely to jam once it has been adapted.
Safety is paramount when working with firearms and the last thing actors want is the weapon jamming mid-stunt.
Dramatic effect also has a large part to play and explains, for example, why some scenes show the hammer being cocked when it was already prepped to fire.
Professional armourers should always be on set when weapons are used, unlike in the case of Brandon Lee, who was tragically killed in an incident involving blank ammunition that failed to fire as expected. A process that would likely have been checked had an armourer been on set.
On-screen examples of weapon errors include Hollywood military movie 'G.I. Jane' which shows an attack helicopter flying off to battle with empty rocket pods while one of the biggest flaws in British TV drama.
'Our Girl' was that of the Sight Unit Small Arms (SUSAT) being back to front on her rifle.
Good Military Advisers are worth their weight in gold to directors and their advice can make or break how well a film is received, particularly among the vast number of serving and former Armed Forces viewers, who tend to be extremely vocal when they spot errors and omissions on-screen.
The film 'Flyboys' was widely criticised for its lack of accuracy and many military inaccuracies. It was later discovered that the military adviser was a fraudster who had lied about the extent of his military service.
Paul Biddiss, ex-Para and Military Adviser, has worked on sets including 'The Monuments Men', 'The Last Post', 'Fury' and '1917'. He describes a key part of his job as being able to: "Maintain a balance between Hollywood and realism and find a compromise" with the director.
Ultimately though, an adviser is there to 'advise' and the decision as to whether their recommendations are used is ultimately up to the Director.