I measure every case after sizing and keep them all within .0005 for both my 6 BRA and 300 SAUM IMP. The Prazipress is a big help there. Sometimes I need to size a case a second time to get it there.
I measure every bullet after seating and also keep them to within .0005" for my record rounds. I just started measuring the 6mm Roy's for OAL--like Roy told me to do. I will also begin experimenting with pointing and trimming.
With the Berger's I am currently shooting in my 300 SI, I am measuring and sorting them by BTO as well as base to seater stem. I will also start experimenting with pointing and trimming these.
I had a tuning disaster last Friday before the match. I had loaded two ladders for the 6 BRA and one for the 300 SI. I over adjusted my scope and put all my shots low off paper.
I wasn't terribly worried about the 300 SI. I did very well the last match and the 300s are forgiving. However, my 6 BRA LG has further to go. I managed to "borrow" some primers and loaded up a three group test: + .006, +.009, +.012. Like last match, +.006 shot well, but +.009 was out. +.012 started to come back. The +.006 was a 3" group--decent, but not yet where it should be on tuning day.
When
@GlennK saw my target he asked why I didn't shoot .005, .006, .007. The answer was because in prep for this match I had failed to bug Glenn and
@tom like I should have. You see not only are these guys two of the best, they expect you to bring your A game and expect to help you get it there.
Those are the two I bug the most about tuning. I also bug
@Alex Wheeler about chambering barrels and
@Northridge about match procedures. While either of those guys could help me with tuning, I gotta spread the peskiness around....... BTW, Alex's tip allowed me to finally cut a 5R chamber with nice straight rifling ends (vs U shaped).
But I digress. The key to consistently shooting small groups Deep Creek is testing very small changes, like .001" seating depth increments. To see those small changes everything else has to be up to speed--loading, tracking, and wind analysis.
So for tuning on Friday before the Aug Match, my 6 BRA ladder will be +.005, +.006, +.007, +.008. Maybe I should add +.004 as well--I'll definitely ask Glenn. I'll also have some vials ready to test .1 grain either side of my 30.9 charge.
For the 300 SI, I'll test what I meant to test last Friday: 61.6, 61.8, 62.0, 62.2. The 200 grain Berger Hybrids are very happy at +.021. I know .2 grains seems awfully small in a 60 grain charge--kinda like a .1 grain change for a 30 grain charge; but we do see these changes on target. And I know there is a 3 in my 300 SI HG--after all, I did that last year with a cobbled together 300 WSM using inferior brass but tuning it in .2 grain increments.
Also, I need to give just a
little more 30 cal competition to my buddy
@Throwin Lead.......