does anyone have any loads that give good accuracy and high velocity with sierra 140MK. i'm getting very good accuracy with imr4831 but can't get velocity over 2725fps from 30"bbl. when i go over 46 grs. velocities become erratic and accuracy goes.

swamp:
H4350 @49 to 50g will give you 2950 to 3050 in most good barrels with 140/142 pills.

2950 to 3000 is the window where most accurate loads are. There is another node a little over 3100, but barrel life gets a lot shorter.

HTH

Alan

thanks alan, i will start at about 45 grs. and work up and see what happens. if that works it would be great as i have 8 pounds.

These are extremely stiff loads which were worked up to in my rifle, all cautions advised and strongly suggest you work your rifle up as well. I also believe that greater accuracy will be yours at 2950 to the upper limit of performance in your rifle. Mine is a Rem 700 with a Hart barrel at 27", 1 in 9.