Originally Posted by DAVETOOLEY
So let's see one 10 shot group at 600 yds. published in1971 in the American Rifleman is gospel.
You forgot I mentioned he shot several others about the same size. Later that day, he put 40 shot inside 1.93 inches at 600 with the same ammo and rifle. But it's OK by me if you dismiss this or ho-hum it by other means.
One test at Sierra in the tunnel out of a machine rest, probably shooting 168's- big deal.
Wrong, but yes, it's a big deal. Sierra first ballistic was also a top level high power shooter. When he tested production runs of 30 caliber HPMK's, he had dozens of full length sized, primed and powder charged cases (metered, not weighed) ready to have bullets seated and shot from rail guns in their 100-yard test range in California. 168 and 180 HPMK's were tested in .308 Win. cases; 190 and 200 grain HPMK's were tested in 30 caliber belted magnum cases. As the cored jackets went through the final stage pointing machine, he would grab 10 of them, seat 'em in those cases then shoot them. When those 10-shot groups got down into the ones (indicating a very uniform lot of jacket material and very uniform jackets), he would move a special barrel under the pointing machine. As long as test groups were in the ones, those lanolin coated ugly bullets went into that barrel. When test groups went up into the twos and threes, he moved a production barrel under the pointing machine, scraped the top inch or so of bullets out of the special barrel then put them in the other one. That production barrel went to the rubber lined cement mixers full of wood chips where the lanolin was removed and bullets polished bright and shiny for packaging in green boxes.
Meanwhile, that special barrel's bullets would be packaged in 1000 round plain brown boxes, a blank shipping label affixed then in pencil the bullet weight and caliber would be written on the box top. Those bullets were shipped to two folks who sold them at high power matches to anybody for abot 10% less than what green boxes retailed for. They shot about 40% more accurate than those sold at retail in green boxes. I've still got some 180's, 190's and 200's in those brown boxes. Sierra quit this practice when they moved their plant to Missouri. I've tested them in my '60's era 30 caliber magnums with both full length sized and brand new cases getting 5-shot group averages around 3 to 4 inches and 20 or 30 shot test groups wel under 6 inches.
I was fortunate to get a couple 1000 bullet special boxes of 30 caliber 155's to help the US Palma Team develop loads for that bullet in 1991. I shot 20 of 'em into 3.2 inches at 800 yards. A friend grabbed 20 of 'em at random from a Dillon 1050 progressive loading them in brand new cases with metered charges of IMR4895 under bullets with runout of up to .004 inch then shot them into 2.7 inches at 600 yards with his ' 60's era pre '64 Win. 70 based rifle. I had the high aggreate score over 5 days shooting them in the first long range match in which that ammo was used by everyone. Group wise, over 95% of my shots stayed in the 600 yard 12-inch 10 ring and the 20 inch 10 ring at 800, 900 and 1000 yards. None were more than about 1.5 MOA away from center.
It's ok by me if you thumb your nose at this too.
Smart folks know that a long range benchrest aggregate record in the 5 and 6 inch range includes some groups larger than the average. Statistically speaking the big ones go up to about 50% larger. Realistically speaking, sometimes the biggest one is twice as large, but the smallest one has to be tiny to get the average well under tha biggest one. But benchresters don't like to discuss nor mention the biggest groups they shoot; doesn't matter that they happen just as often as the smallest ones.