TNTs are great for sage rats---------they look like they were shot with a larger gun than a .222. I discovered 2200 about 15yrs ago too, and still have a pretty good stash. 26grs and TNTs in my .223 Ruger UL (20" barrel) yields 3450fps and bug holes. I've stuck with 20.5grs 4198 in my 222 though. Messed with BLC-2, AA2015, and one or two others (too lazy to find notes), but have never bested 4198. Ball powders do throw nicer, but what the heck.
BTW, not to hijack your .222 thread, but after 2200 dried up, I discovered 2230C priced equally cheap, and it turned out to be a superb .223 powder. The good old days of 10+ yrs ago!
