What i have been using in my X7 with good results is Winchester 209 primers, green crush rib sabot, 270g gold dot, and 105g BH209. This load does make for hard fouling in the breech plug, but it is a way more accurate than i can shoot with the peep sight. I read here or on another forum of a way to clean your breach plug very easily. I am kind of hesitant to recommend it to you, but it works so good i must pass the information on, but beware; don't use this in your barrel, only on your breech plug, and be sure none remains when you are done.

Windex multi-surface cleaner really really cuts the hard fouling on my breech plug
readily, and makes cleaning the breech plug a pleasant experience, compared to using anything else i have tried. However, it will rust or promote rust in your barrel, and i will not use it ever to clean anything but the breech plug. The hard carbon fouling literally falls off the breech plug when one uses this stuff. I hope, if you try it, it works as well on your breech plug as it works on mine, but i also strongly recommend you never use it in your barrel or anywhere else in your rifle.