some very sound advice given above.
i have found that if you clean and inspect your pellets, it helps to upgrade performance.
i have had good luck with some pointed pellets at 50 yard+- ranges after cleaning, inspecting and cleaning off any 'swarf' left from the casting process.
you might also consider weighing and sorting pellets...they do vary some in weight. (especially the lesser expensive ones...)
it's truly odd, but i've found that most pellets will perform to a high degree of accuracy when YOU do your part with all other factors being equal. but overall, yes, domed pellets seems to offer the best, most consistant, accuracy/performance.
i happen to have really, really, good luck with JSB exact king match domes and Beeman Silver Ace from my .25 Mrod and the same with Beeman Silver Jet/Arrows and RWS Superdomes from my RWS 52. my AF Talon will digest nearly any thing very accurately...
you've probably found by now you cannot use a non-springer rated scope on a springer...the open sights idea is a good one. i personally prefer open sights whenever it's practical. in fact, i have upgraded open sights on several of my air rifles.(rifles like the Benjamin Marauder are not designed for open sights, as an example.)
open sights are not as accurate at longer ranges but the critters i hammer with them don't complain...they just die.
it's all subject to your likes and dislikes...experiment and have fun with it...