6mm Match Bullet Diameters
There’s been some controversy surrounding the “ideal” 6mm bullet diameter. This is compounded by the fact that 6mm match barrels are available with both .236″ and .237″ land diameters. It has become quite clear to us that bullet diameter is an important variable to consider when choosing the best projectile for your particular barrel. Some barrels prefer “fat” bullets while other barrels prefer “skinny” bullets.
Jason Baney recently took the time to measure 12 different sets of 6mm Match Bullets, including a couple different lots of the same bullet design. Interestingly, Jason did measure the “old” Berger 105 VLD, the “new” Berger 105 VLD (first lot from the new die), and the “new, improved” Berger 105 VLD from the new die, after it was polished. Ten (10) Bullets were measured per type. Each bullet was measured three times (3X) around the largest circumference, normally where a pressure ring would be located (some bullets have a pronounced pressure ring, others do not).
Download this CHART as an MS Word Document.
Columns one and two of the chart show the smallest and largest bullet diameters measured for each 10-bullet sample. The third column shows the extreme spread over each 10-bullet set. Note, these numbers are NOT averages, but represent the “low” and “high” diameters for each set. (FYI: Jason noted that while the Lapua Scenars measured very consistently the earlier 2005 “JEVDAK” lot had noticeably smaller meplats than the current 2007 lot.) A Mitutoyo Micrometer was used, zero-checked for each bullet.
Great information, but would still lke to hear the rationale for choosing the .236 or the .237 bore diameter. Specifically, I shoot from 200yds. to 600 yds. with 105 to 107 gr bullets. So which which bore diameter would be selected and why ?
Thanks for your help.