I know it's rude to answer a question with a question and I'm going to ask a few, so forgive me.
What hulls do you want to use?
What wads are you using?
Do you want 1 oz or 1 1/8 oz loads?
Light or heavy. 1150 or 1200?
Have you seen the price of a 25# bag of shot lately? I put up my reloaders as it's cheaper to buy Win AA by the Flat than to reload for standard trap, skeet, or sporting clays. I still turn out specialty ammo for hunting and shooting games.
If you buy shells. Remember trap rules limit you to 1 1/8 oz max and 1200 FPS 7.5 shot or smaller, if your planning on ATA. So no handicap loads.
I reload the Red Win AA hulls with 19.5 grains of Green dot and WinAA12 wads with Win 209 primers.
I use green dot because I can use it in My .45ACP, 20 Ga and the 1 1/4 oz 10 ga loads. I also reload Blue dot for it's many uses as well.
Speed is based on a 28" barrel and will go up with a 30 and down with a 26" But only 10 FPS each way.