All shogtuns are finicky when it comes to ammo. One brand that does wonder in one gun, can be horrible in the next.
What are shooting or restrict to shoot? sabot/bullet slugs ( foster brenneke style )?
I would buy a bunch of everthing that I can get my hands on. Get a roll or bag of sand, and buy a few targets. Try them all and only after this action, then select the top 2 brand.
I'm using brenneke original magnum ( 75mm 1oz ) out of a 12ga with 4x Nikon scope on a 870 super express with a hasting cantilever bbl 24" . That's my deer or bear gun if I was to hunt with a 12ga non-buck-shot load. This load is good for me to 100yards in my hands and with my eyes. It's milder in recoil, when compared to some other brands.
I've also used the remington 1 1/16oz sabot and buck-hammer with various deg of success.
I found that most rifling slugs do not improve out of rifled bbls. So each to his own and YMMV