During my trap shooting days I owned a BT99 Plus. It had an adjustable buttstock, comb and rib. The only criticism of these guns was the rib was somewhat fragile and owners needed to be careful the rib didn't get damaged. If you are considering a used one then pay close attention to the condition of the rib. I've seen several BT99 Plus where the rib was noticeably bent.
Other than that they were a good gun. If you do get one I'd heed the advice I was given to pattern the gun, adjust it until it shoots where you want and then throw the wrenches away. The temptation to make adjustments to the gun after a bad round or during a slump is almost overwhelming.
Mine was sold to finance a Beretta 682 o/u when I got the bug to shoot other games.
