I throw my charges with a Chargemaster also. While this is not typical, I looked through my load book and found this 5 shot string:
240 SMK @ 2.21", 9.4 grains VVN110:
1121
1122
1123
1123
1120
That just shows that it IS possible to have VERY low StDev, if only occasionally.
That is out of an AR. Between VVN110, 2400, and 1680, the VVN110 is the winner when it comes to consistency. Most of my velocities for a given load vary no more than 50 fps from lowest to highest velocity. Try some VVN110. It's a good thing it lasts so long with this cartridge, because it's been my experience that it isn't an easy powder to find.
-Dan