One of the local IPSC clubs is going to be holding a shotgun side match from now on. Beyond knowing that I should bring my shotgun (Remington 870, Ashley Express sights, 7 round total capacity) any words of advice on ammo selection, gunhandling, practice, etc. would be greatly appreciated. I can put slugs into a tighter group at 25 yards than I can with any handgun if that's a help.... Thanks,