attack while walking

[A-Man]

Only worthwhile ways I can think of are:
1-(Ab)Using the hitback technique, but you'd need to reverse the facing direction of the player before and after the move is done. This means that your character wouldn't be able to walk "back" in that state either during that move. Being hit in the middle of the move would take you to the injured frames with wrong facing however, so I wouldn't recommend using this technique.

2-You might want to take advantage of the fact that your character uses a gun as an excuse to why your character isn't able to hold heavy weapons, and use the heavy-walking frames for your move.