Triple7 said:
If I'm using a Mod choke is it going to make huge difference?
Yes, You are way overchoked. Skeet is a close in game. That's why they make SKEET chokes, which are .005 constriction. Your Modified chokes have .020 constriction, which is 4 times the needed constriction. Some people even use Cyl. bore choke tubes, which I do not recommend, but your Modified chokes are handicaping you, so you need to change them.
If you are not going to reload, then any brand shells will work, but if you intend to reload, then you should be purchasing shells that reload well. All premium shells reload well, and the cheaper Remington Gun Clubs reload well. For that matter, any remington hull of recent production reloads well. Avoid the cheap Winchesters and Federals. For 12 and 20 ga. skeet, use #8's, or #8-1/2's, or #9's. All work very well.
DLM