If the purpose of journalism is to inform, then the information provided should be accurate.
Additionally, an unspoken goal of any information source is to be valuable, and an information source is only valuable if it is trustworthy. Thus, the information provided should be credible. Information is only credible if it is accurate and unbiased.
Accuracy
Accuracy is challenging for any technical field, particularly one practiced largely by laypersons. It is common to discuss firearms with casually ambiguous or even incorrect terminology. When repeated out of context, or in a new context, that information is often misunderstood or simply wrong.
For example, there are more than twenty common .22 caliber cartridges, so when someone says, “a twenty-two”, do they mean the .22 Long Rifle caliber, or could they be referring to one of the others? And if you ask them to clarify, they may lack the precise terminology needed to clear up the ambiguity.
Another example: A police officer may refer to a magazine as a “clip”. Though this is incorrect terminology, it is common. Should a publication repeat this incorrect usage as their own? Much of the audience will take note, and some will log feedback. Should correct terminology be substituted? Certainly, but probably not in a quote. However, “clip” can actually have a valid use, so how does one know which is the case?
It seems to me that the solution here is to understand what has been communicated, rather than simply trying to repeat it back. Certainly, one should try to avoid paraphrasing within a topic that is not understood.
Bias
It is a well-understood phenomenon that news reporting media is heavily biased when reporting on gun-related topics. It’s outside the scope of this site to advocate for less bias, but if you’re interested, I recommend John R. Lott, Jr’s The Bias Against Guns: Why Almost Everything You’ve Heard About Gun Control Is Wrong.
However to some extent, the way you write about guns can inadvertently introduce bias, or the appearance of bias. Technical inaccuracies, conflation of facts, incorrect assumptions, and simply demonstrating a lack of understanding all work to erode your credibility.