You can use it for fast 1 1/8 oz loads, but it is dirty and not well suited for the task. It is also not very economical as it takes a bunch of it. If you try to load it down it will not burn very well. It is better used for 12 gauge 1 1/4 oz Field (3 1/4 dr) loads. Works well with 16 and 20 gauge shells too. Only if it was free and I didn't have anything else I would use it to load 1 1/8 oz.
There used to be 3 3/4 dram 1 1/4 oz (1330 fps) loads listed, I shot a bunch of them, but they disappeared after Alliant bought Hercules Powder Company.
I am doing this from memory. Remington Nitro STS hull, 25 grains Herco, AA12 or replacement wad. 1 1/8 #7.5 and a win 209. Ive used it for games. I gave the load info to a friend for games and now he said he is going to use it for windy day caps. (?)
I to like 800x better, but I would take either one in todays powder poor climate.
A good 1 1/4 load. Win AA hull, WWAA12r wad, 26.5 grains Herco, Win 209 primer. Patterns well for me
I still use Herco for 1 1/4 ounce pigeon loads, but at about 1225 fps. Unfortunately, I have a bunch loaded, will probably load no more. At ten bucks a pigeon at shoots and seven bucks for practice, I use them very slowly.