Zero to 1 Mile

FOR ME YEARS I had contemplated building a long-range rifle, preferences ranging between a 6.5mm Creedmoor and a 338 Lapua a Mag, with several others in between. Years ago, I had bought three barrels to replace older ones and also with this plan in mind. Two were in 7mm and one a 6.5mm. I had w ed both 7mm barrels to have a 1 in 8-inch twist but the s ec sheets each showed 1:9.4 – one a stainless steel 431 and the other a CrMov1210. The 6.5mm has 1:7¾ inch twist CrMov1210, perfect for a .260 Rem or a 6.5 Creedmoor.

The bullets I had in mind for the 7mm were 180gr Hornady ELD-M with its astonishing G1 BC of 0.796 (G7 .401). Some internet forums reported on using this bullet and having to correct the BC to 0.810 (G1) to get the DOPE in a 1:8 inch twist barrel to match their ballistic charts at 3 000ft altitude. This means the ballistic efficiency will be higher at the 4 500ft altitude at which I mostly shoot. Range tables out to 2