My maternal grandfather was a forward artillery observer. He started on D-Day, got caught up in the Battle of the Bulge, and went all the way through to the end. Not many of his friends made it that far.
I only recall him making two firearms references. He said that, "All I had to defend myself with was a lousy 38." I assume it was a Victory model? Apparently I didn't learn much from that, since I carry a snub 38 fairly often.
I don't recall his exact words, but he
really, really, really didn't like being shot at by German 88's. After reading up on it, once the Germans realized that they were being subjected to observed fire, the 88's were probably useful for direct fire at all of the spots they figured an American FAO might be hiding in.
He grew up on a farm, but he said that he didn't learn how to dig really fast until people were shooting at him.
My impression was that he would have preferred a 1911 or carbine, but he was too busy with his actual work, and his enlisted men protected him as part of their jobs.
My paternal great-uncle was a "belly gunner", I think on a B17. He was quite pleased with the effectiveness of his 50 caliber machine gun. He highly recommended it for problem solving. After his wartime experiences, he felt that handguns were laughably puny. IIRC, he kept a 32 revolver in his pocket when he was at work (construction foreman), but didn't have much confidence in it.
I have faith in my relatives' advice. I would very much prefer to use a 50 caliber machine gun ("Ma Deuce") or 88-millimeter anti-aircraft gun for SD. They aren't particularly legal or convenient, though, so I will have to settle for my 38's, 9mm's, 45acp. etc.