Ogive differences

I thought BR guys measured their groups with microscopes. There is one local next weekend, I might go watch it just for grins
 
Thought of this thread as I loaded 30 rounds of 6.0 Creedmoor with 107 grain Sierra Match Kings. Seated with Forster micrometer die on my new Lee Turret press. I checked all 30 using a Hornady gage on Starrett 120A calipers and all 30 were within .001 base to ogive
 
yeah I read the story on the 1000 yard match on another site. Even the guy who shot that .1 was amazed at that group
 
Those 1000 yard record's 10-group aggregate sizes listed in post #64 best define the accuracy one can count on once in a while. All the other aggregate sizes that rifle and ammo shot are bigger. Largest single group in an aggregate record is typically 20% to 30% larger than the aggregate/average group size. Sometimes 40% larger.
 
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Last year I did a study on .22LR and their base to ogive measurements. SK Pistol Match,CCI Std Velocity, and Lapua Polar in that order always give me the best groups in my CZ.

Coincidence ?

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also just did some measurements on my new lot of 77SMK's. Average BTO of the bullets is .015 longer than the old lot. Seating would not be affected but case volume would be reduced by a minute amount
 

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Bart, shooting groups will vary due to shooting condition as you know. You picked time place for your small group vs in a match.
 
shooting groups will vary due to shooting condition as you know. You picked time place for your small group vs in a match
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A very experienced and successful shooter gave me a nugget of wisdom at the end of last season. Practice under ideal conditions to show what you may possibly shoot in a match, then shoot the same rifle ammo etc when the mirage is boiling and the wind is blowing in three different directions and you will see what you will probably shoot. Matches don't always happen on a windless cool morning with a cloudy day.

my last practice day with boiling mirage and a slight tailwind. Even at 200 my twenty shot average shot grew by .5 MOA from shooting the same targets with the same rifle and ammo as I had the week before. That day had been calm and overcast and a perfect morning for shooting.

.5 or even higher 10 shot groups seem common when running with the big dogs at the major matches depending on wind and mirage

Pa World Open Relay Results

Williamsport World Open 1000-Yard Championship match writeup. Beautiful range but that terrain would make for some tricky winds.
 
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