When I was a kid, I had an LDS friend whose grandfather served during World War I and had, for a while, been assigned to the firing squad. He would brag to me (more than once) that he was proud to say he never killed a man while on that duty. When the command was given to “Aim!” he’d point his rifle slightly to the side of the prisoner, so when it was time to “Fire!” he’d always miss. Of course, others in the squad would aim accurately and kill the man, but the grandfather’s conscience was clear. He said he knew the feel of a live round, and he wasn’t about to find out after the fact if he had one. He was pretty tickled, too, about how he had fooled the army. Unfortunately, when he confessed it to his bishop, it cost him his recommend (dishonesty, disobedience, dishonor, something like that) and got him a major tongue-lashing. He never regretted his choice, though and, of course, he did eventually get another recommend.
Personally, I can’t see the Lord agreeing with the bishop on this one.