@Bigdave, @spaceghost, and everyone else…
I am in agreement with all of the concerns posted about why a colony ship 136 years in the future is still using gas driven carbine weapons systems: Aka the M4 modified M16 stemming from a war in the 1960s. So in actuality it is almost 200 years later.
I agree after this amount of time there would be major weapons advancements.
So let us all dissect this a bit further.
First thing to consider: From the prologue in Alien Covenant David communicated everything that happened on LV-223 back to the Weyland Corporation.
All of the weapons systems employed by the Prometheus crew were ineffective against the Engineer, Dr. Holloways' mutated form, and the trilobite creature that Dr. Shaw encounters after having it surgically removed from her womb. The trilobite even kills the Engineer.
Second we must also postulate that David has communicated this information to the Weyland corporate executives by way of the Prometheus “life boat”. In this communication he must have given highly detailed information about the crews encounters and the weapons employed.
Thirdly the Engineers have technology that is 10,000 years more advanced than our human technology. For example space ships that can travel though out our galaxy. Sleep chambers that allow Engineers to hibernate for 2000 years or more. Obviously they have very advanced bio-technology capabilities.
Fourth, we all know that despite all these limitations that the Weyland Corporation sends 2000 of these colonists, with what are essentially almost 200 year old gunpowder based weapons to fight highly advanced alien beings.
So is this a strategy of the Corporation to ensure they collect the alien? Has this all been designed to fail from the start for the crew and colonists?
In the trailer where Walter is out with the expedition crew he stands there doing nothing as another proto-morph is jumping out of the throat of one of the crew members. He does absolutely nothing. He stands there as if nothing is happening at all. That should be a big clue as to what is really going on with all the intentions of Walter and the Weyland executives.
Also, just to keep things in the correct context, we have to understand that if they landed and had weapons that were too powerful the crew could easily kill all these different Aliens and there would be no action or point in making a movie just about this type of plot.
Another thing to consider is that the audience may not be able to understand or care about all the factual details of a plot they do not understand at the level we do.
In addition to all of this we still must consider that chemical based weapons cannot be affected by EMP fields and so as being analog and mechanical they are more reliable under a broader range of conditions.
Highly complicated specialized weapons may not be repairable, replaced or more importantly be used because the highly dense energy they require cannot be 3D-printed and synthesized fast enough from ground based productions.
I think we would have had a better movie if in Prometheus Peter Weyland commands David and crew to capture the Engineer in stasis. It is conceivable David could have learned about the ship and its computers to keep the Engineer in suspended animation and then take the entire Ship back to Earth.
However, Ridley Scott likes to make movies that appeal to the widest range of audience members and does not like to stray too far from formulaic plots.
Of course we know that Mr. Weyland would have captured that ship and its Engineer and gone back into hyper sleep himself for the return journey back to Earth.
We can all debate these inconsistencies in plot, aesthetics, and what audiences can relate to but I do not think it really matters much because the general public is paying to watch this kind of production, so no real critical thinking comes into play. Great movies from years ago made audiences think more critically about how everything in the film relates to plot because they did not have the type of special effects that we have today. Contemporary younger mainstream audiences are pervasively connected to the larger social networks of the Internet and thus are reading far less than previous generations. Audiences today are not as good at critical thinking which is essential for understanding and developing anything of real substance.
Ridley is obviously a visual producer and weighs more heavily on how a movie looks as to how well the plot functions. He got lucky with Alien. I think he did not consult or try to employ enough expertise from science fiction writers to put this all together more convincingly in Alien Covenant.
Ridley is not a great science fiction writer and never will be. He is a director-producer and this is what we see in his films. Well respected film critics have been vocal about this in the past so there is no changing it now.
I still think the movie is worth watching if for nothing more than the great visual effects because I like to think in the same way as a painter, and also as someone that appreciates masterful design through art.
As for the general audience suspension of disbelief comes at a cheaper price. Just know that all of you require much more in order to be convinced by these types of thematic illusions.