MemberDecember 15, 2017 at 6:36 pm1 Bullseye
Yup! I use a magneto speed chrono. I also trust my scope, SWFA 16x. Never had a problem with tracking. I know my system works because I have scored first round hits with my .223 out to 650 yards in my standard conditions, and also at 680 yards in Wyoming with a 3000 foot elevation change! When I use the velocity from the magneto and the higher bc, it matches exactly the results I get from 300-600 yards, so hopefully when my friend and I can get out to longer ranges we will see how it matches up.
On a side note, I never go by 100 yard groups. For one… I can't afford it haha. I get one box of bullets and work up a load in as few of rounds as possible. I shoot a latter test and go by velocity. Then I do an ocw test to really narrow it down. I usually can get it done in 15 rounds, and under 10 rounds if i just go right to the higher end of charge weights.
I actually never test at 100 yards. Like you said, when I first started reloading I'd go for 100 yard groups alone, but i found out this does not guarantee long range accuracy. Now i test at 200-500 yards and I test for least vertical dispersion and tightest velocity spread.