Quote Originally Posted by eddiesindian View Post
IMO...all you can do to tighten up #s is make sure that all of your powder charges are exact, every single one. including same brass,match primers/match bullets/same barrel temps, cleaned/semi clean barrel/outside temp. etc...
As I mentioned before. To me, its more important to do your homework on working up loads thru ladder test and work on figuring out how much propellant, what brand, how much,which projectile,which weight of projectile works best thru your barrel.
As You can ask any reloader, theres no better feeling than shooting 5 rds at 100yds and the results are 5 holes touching each other...when that happens?...you break out your chrono and see what the "majic" speed is.
Good luck
This is spot on. I work up the load that's most accurate in MY rifle, using assorted powder, bullet, and seating depth combos. When I hit the one that shoots 1/2" (usually less), I'll chrono it for purposes of drop and windage charts. The FPS is what it is.
I ended up with Berger 80gr VLD's over Varget, with the OAL just kissing the lands. That has given me a best 5 shot group of .210" @ 100 yds. After all that, I used a chrono to see 3050fps. Now I know my 600 yard drop and can calculate for the wind.

The best you can do to have good numbers on a chrono is to be consistent in your loading procedures.
Consistent brass prep, charge weight, seating depth and neck tension are all I ever worry about.