Recently I purchased 5000 6mm Bullets of the same manufacture (big named bullet maker), caliber, weight, and type.
They were measures for weight, over all length, bearing surface diameter, length of bearing surface, length of boat tail, length from bearing surface to meplant. I discussed my findings with the manufacture and the President of the company said the tolerances were with in spec. The weights were within +/- .2 grain. The Overall lengths were with in +/- .003", the length of the boat tails were +/- .003" the lengths of the fronts bearing surface to meplant were with in +/- .003", ironically the bearing surface lengths varied +/- .030".
Test were shot with the same rifle, brass, powder, primers, same temperature. The only variable was the extreme bearing surface lengths. There was a consistent velocity extreme spread of 50-60 fps between the to length variables.
I have noticed variables in bullet lengths between different lot numbers of the same bullet type and weight, but so drastically with in the same lot.
Testing of another premium bullet manufactures bullets I found the 150 grain 308 bullet shooting erratically with a proven load during prior loadings. I measured the bullets weight, Over all length, and they were +/- .3 grains and +/- .003" in overall length. To my surprise the bearing surfaces measured .308" at the front of the bearing surface and .3065" in the rear of the rearing surface. The rifle had been shooting sub .5 moa at 100 yards and all of a sudden with the new bullets went to shooting 4.5" moa at 100 yards.
I bought 5000 (.308/185gr) and 5000 (6mm/ 106gr) custom made bullets from two different bullet makers and the specs were much tighter tolerances. The 6mm bullets groups at 1000 yards averaged 20% smaller than the off the shelf bullets.
My conclusion is with the extreme high demand and production that factory bullets quality has suffered. I believe the benchrest shooters have proven winning with custom made bullets is a more frequent event than winning matches with unaltered factory bullets. Many of the winners shooting factory bullets have spent hours weighing, measuring, and pointing their bullets. In my opinion the extra money spent on custom bullets is a well worth it if you take the time and effort spent on factory bullets.
Nat Lambeth
They were measures for weight, over all length, bearing surface diameter, length of bearing surface, length of boat tail, length from bearing surface to meplant. I discussed my findings with the manufacture and the President of the company said the tolerances were with in spec. The weights were within +/- .2 grain. The Overall lengths were with in +/- .003", the length of the boat tails were +/- .003" the lengths of the fronts bearing surface to meplant were with in +/- .003", ironically the bearing surface lengths varied +/- .030".
Test were shot with the same rifle, brass, powder, primers, same temperature. The only variable was the extreme bearing surface lengths. There was a consistent velocity extreme spread of 50-60 fps between the to length variables.
I have noticed variables in bullet lengths between different lot numbers of the same bullet type and weight, but so drastically with in the same lot.
Testing of another premium bullet manufactures bullets I found the 150 grain 308 bullet shooting erratically with a proven load during prior loadings. I measured the bullets weight, Over all length, and they were +/- .3 grains and +/- .003" in overall length. To my surprise the bearing surfaces measured .308" at the front of the bearing surface and .3065" in the rear of the rearing surface. The rifle had been shooting sub .5 moa at 100 yards and all of a sudden with the new bullets went to shooting 4.5" moa at 100 yards.
I bought 5000 (.308/185gr) and 5000 (6mm/ 106gr) custom made bullets from two different bullet makers and the specs were much tighter tolerances. The 6mm bullets groups at 1000 yards averaged 20% smaller than the off the shelf bullets.
My conclusion is with the extreme high demand and production that factory bullets quality has suffered. I believe the benchrest shooters have proven winning with custom made bullets is a more frequent event than winning matches with unaltered factory bullets. Many of the winners shooting factory bullets have spent hours weighing, measuring, and pointing their bullets. In my opinion the extra money spent on custom bullets is a well worth it if you take the time and effort spent on factory bullets.
Nat Lambeth
