I am working on loads for a Ruger Hawkeye in 257 Bob. I am using 87 gr. Sierra Varmint bullet, WLR primers and H-4895. Bullets seated .010" from lands. This is my first attempt at a varmint rifle.

Average velocity for 40.0 grs is 3113 FPS. Best 3 shot group 5/8"

Average velocity for 42.0 grs is 3313 FPS. Best 3 shot group 1 1/8"

With a 200 yrd. zero this breaks down to a difference of 2.92" drop at 400 yrd.

Not bad for 22" barrel.

Anyway 40.0 seems to give the better group. I'd like to go with 42.grs for the simple fact that the velocity is what I want. This rifle is primarily for groundhog hunting.

Will moving the bullet in .010" increments tighten my group up?

Or is the difference in drop not worth it?

My opinion would be to use the most accurate load. If you want more speed change powders until you get the desired speed and the required accuracy.
If you are hunting varmints your 5/8" group at 100 yards becomes a 2.5" group at 400 yards (at best) your faster load at 400 yards prints at least a 4.5" group which may be too large depending on the varmints you are after.
I would go with accuracy over speed everytime, some opinions may vary but if you don't hit it then it matters not how fast the bullet was going!