I run the same gun. And have been using Carlson Extended Sporting Clay. In both I/C ported and non ported, and LM non ported.
We run a bunch of handloads that run pretty fast 1600 fps plus. On the odd chance we encounter an issue, it is usually in the choke. With the extended choke, you have lots of play to engage a pipe wrench.
My go to load is RSI 65+1 in 2 3/4 B's. But when I use factory, it's Kent 2 3/4 or 3", 1 1/8 of 1's. I have bought into the speed kills theory, and spend lots of time putting it on paper to make sure. We hunt mainly Canada Geese in Ontario, Canada, and have never had a problem putting them on the ground due to shells and chokes. I had to switch to the I/C choke because the LM was way to tight under 45 meters. All I can say is try to borrow a few from buddies, and pattern the loads/choke. Every gun will be different, even if it is same make and model.