Re: Using BRANDs in your work.
I agree with the added flavor. Consider this, when a comedian uses name brands like Toyota, instead of: a car, it's always more comical. I always try and use name brand guns, and cars, because it gives the reader a visual of the scene, and also I believe offers up that the character knows what they are doing.
If I had a marksman say he cleaned his M24, instead just cleaning his gun, it makes him sound like a true professional, and not just a hobby of his.
My two cents.