Thread: Biggest influences on getting low velocity SD

annealing brass, charge weight accuracy, seating depth accuracy, trimming, sizing accuracy, finding the sweet spot with a charge ladder then minimising as many variables as you can with all the previous listed.....you could go deeper into the rabbit hole and start neck turning and batch weighing brass and projectiles it really depends how far you wanna go.
Of course a good magnetospeed chrono or labradar or you might as well take @Micky Ducks advice.....(Jandal thrown )

personally once I have found my load with lowest E.S through a charge ladder, then you can fiddle the seating depth to tune accuracy if required.
then my process for loading is
*Anneal brass
*Full length size
*wash/clean (I use a ultrasonic, but feel free to use whatever works for you, tumble, other magic potions etc) just make sure you clean the lube out and dry your cases thoroughly
*clean primer pockets
*trim
*chamfer, inner then outer (just my preference)
*Prime
*load charges
*seat projectiles (I use a small container of stainless shot lubed with powdered graphite to lube the projectile base). I usually measure the first 5 as I go to make sure my seating is consistent, then just go for gold and only stop to measure if I get a case that feels different (i.e: more or less force required to seat the projectile)

My loads are well consistent enough for the ranges I hunt at shooting a 270WSM and consistently shoot 1/2 MOA or better groups with boring repeatability.
I am no bench rest shooter and I certainly don't have the latest and greatest gear but I have what clearly works for me, and the above without going into more detail certainly works. this is what I have come up with under the guidance of many guru's on here and other contacts.