Love your videos sir, thank you for all your effort in getting them online.
May I suggest that you check out this video that speaks about microphones and video.
http://www.izzyvideo.com/camcorder-microphone/
Or, just leave the gun noise but edit your videos to use closed captioning.
My hearing isn't what it used to be and I always turn on CC when it's available.
Just my 2 cents, keep up the good work!