Just remembered that arsenal made 30-06 match ammo originally had both asphalt sealant in case necks and case mouths crimped into cannelured bullets. When production resumed after WWII in the early 1950's, tests proved accuracy was better when bullets were not cannelured nor crimped in place. The cured sealant had enough grip on the 173 grain bullets to require at least 20 pounds of force to pull bullets from the cases.
The last stage of case forming was to expand the case mouth to a thousandth or more than bullet diameter. But leaving a small "donut" at the case shoulder. The warm sealant was smeared around inside of the case neck then a bullet was seated. Bullets often rested crooked as the sealant cooled and dried.
This is the main reason bullet runout in arsenal match ammo is up to several thousandths. I've seen up to .007" on both 30-06 and 7.62 match ammo.
The last stage of case forming was to expand the case mouth to a thousandth or more than bullet diameter. But leaving a small "donut" at the case shoulder. The warm sealant was smeared around inside of the case neck then a bullet was seated. Bullets often rested crooked as the sealant cooled and dried.
This is the main reason bullet runout in arsenal match ammo is up to several thousandths. I've seen up to .007" on both 30-06 and 7.62 match ammo.
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