I recently had the opportunity to take a shotgun course from the Counterterrorism Institute of America
Topics covered: patterning, combat loading, speed loading, slug change-over, use of cover, shooting and moving, various shooting positions, one-handed manipulation, transition to pistol.
I was using a Mossberg 590A1, VCAS 2-point sling with the A2 buttstock mount, GG&G front sling mount, 3-gun gear side-saddle, HK P30, Comp-tac MTac IWB holster. My goal was to go in with more-or-less the minimum needed. I did not want to deck myself out in a tactical vest, etc.
For ammo I used Federal birdshot from Wal-mart. I've used this ammo successfully in sporting-clays before. I had Remington 00 Buckshot for patterning, and Winchester 1oz rifled slugs. I had ghost-ring sights, and was fairly lucky in that the center of my buckshot pattern with the ammo I keep handy for the shotgun (Hornady TAP 00 Buckshot) and my slugs zero together at 25 yards. I chose the Remington for the course because I had already patterned my rifle with Hornady and Federal 00 Buck, so patterning with those again seemed to be a waste. The Remington has the same center, but spreads much faster. The max distance for Hornady is 25 yards with my gun and 20 yards for Remington. Ammo brand/quality makes a difference!
There was a good mix semi-auto and pump guns. Both pumps and semi-autos had malfunctions at about the same rate. After this course, I still hold fast that a quality semi-auto is as good as a pump, and that pumps can just as easily fail. One pump had an accidental discharge (not a true negligent discharge). This was a slam fire, directed down range. That gun performed fine the rest of the day, though I would not have been comfortable using it afterwards.
Other methods of holding shells: One person used a dump pouch. This was problematic because the shells always came out in a different orientation. One person used a bandoleer, which seemed a bit less than ideal. I think the worst (and it did not get used much) was a shell holding sling. Trying to get shells out of a sling while shooting and moving turns out to be just too problematic.
Notes on my gear selection:
Everything performed more or less as expected. As previously known, the Mossberg must dump two rounds to perform a slug change over. While this is somewhat of a disadvantage, the lack of extra manipulations makes the change-over quicker, and easier. The 3GG side-saddle held tight to the gun, but turned out to be a little too tight at holding the shells. This slowed me down slightly when loading from the side-saddle. The upside is no shells fell out.
My biggest problem was the two point sling set-up would not pull enough slack to perform shoulder transitions. This required me to lean out further than was ideal when shooting around the left side of cover. I chose the sling set-up to be similar to my rifles. My rifles allow me to change shoulders with a two-point; my shotgun, as I found, does not.
I disagree with their idea of birdshot a effective home defense. Their logic with this was demonstrating the effect on a chicken. While devastating on a chicken, a chicken is not very analogous to a human. The muscle is thinner and the bones are not as dense. The chicken is also not wearing clothing. Lastly, the birdshot had a much greater spread at shorter distances than buckshot. I would stick to buckshot form home-defense if you must use a shotgun (which I still do not recommend, even after this course).
Overall, I learned quite a bit. I learned a little bit more about my set-up, and its shortcomings. It was an excellent course, and if anyone is in the area, I do recommend it.