Looks to me like 21 grains of lil gun is just about right for its burn rate, falling right in with H110, 296, 1680 and such, Try loading 20 grains and chronographing it. Next, do you have any AA1680. Quite a few of us are uisng that or the surplus version, and 26 grains pushes the XTP 180 at 2060 fps, and if I remember off hand 22 grians pushes a 200 griner at 1875 from my gun. If you have some and can chronograph some loads with it, there is a better chance of being able to compare velocities to what others of us are getting and then your having a better idea of where the problem lies. Just a thought, JP
P.S. What kind of velocity spreads are you seeing?