I been using the powder coated (homemade) and have been running the 158 gr.
357 loads @ 1050fps and the 240 gr. 44 mag @ 1000fps . I dont get any fouling at all, love these things.
Wow!!! 2800-2900 fps with a 180 grainer, thats sounds like an overcharged batch. Check some reloding manuals, Hodgon website has max loads doing 2600-2700fps ranges with only one load hitting 2800 fps. and that is out of a 24 in barrel, I dont know your barrel length, but I bet it is 22 inches...
If you want to load shotgun shot (shot sizes 9 thru 4) the guys over on Castboolits have a ton of info and load data available. I loaded up some with 6 shot, pretty impressive at 15 feet but after that the pattern starts to scatter pretty quick.