I’ve never participated in cowboy action shooting but that doesn’t mean I can’t learn something from it. In one of the most recent shooting tips videos put out by the National Shooting Sports Foundation, Jim “Long Hunter” Finch shows some single and double loading techniques for a pump shotgun. While Jim is using a Winchester Model 97, his techniques would work just as well with a Mossberg 500 or a Remington 870.
Even if your pump shotgun has an extra long extension tube and you have 7 or 9 shells in the tube, these techniques could be invaluable if you need to switch from buckshot to slugs or vice-versa. I’m no expert but it just makes sense to me to practice some of these techniques regardless of whether you are using the shotgun for hunting or self-defense.
UPDATE: It occurred to me early this morning that if you are trying to load the shotgun while you have a full tube, there are other techniques you have to add in to prevent the round(s) in the tube from loading.