I am going to attend the USPSA 3-Gun championship in Las Vegas and have some questions. The first is how should I carry shotgun ammo since in limited class speedloading tubes are not allowed. Second, what kind of practice should I do for the rifle and shotgun events? I currently shoot in IDPA and USPSA matches every weekend, so I think that my pistol ability is about as good as it is going to be. The guns I am planning to use are a Para-P14, a Bushmaster AR-15, and a Rem 870. Are there any recommendations you might have reguarding my choices?