I can give you a little info. I have a SBE Beneilli and use an Undertaker hevi-shot. Before using hevi-shot, I tried many choke tubes and the best combo I found was a Comp-n-choke ported with Winchester 3 1/2 #6 shot. My dad has a nova and he also uses the Undertaker hevi-shot, before that he used a regular Undertaker but I am not sure what shell he used. It is kinda hit and miss, you just have to buy a tube and try different brands, lenghts and shot size shells to find that perfect combo. It can get expensive.