Re: 260 Rem Load Question
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: P33Shooter</div><div class="ubbcode-body">Compact45,
My loads using the 139sc measure 3.168 COL using Hornady Comparator. Im pushing them out at 2790-2800FPS out of a 22 inch Bartlein barrel.
Im not the best at explaining things but for a rule of thumb VLD bullets like to be jammed into the lands, Berger Bullets are a good example. The 140VLD's like to be at 3.200 COL in my rifle and at the lands the length is 3.178. So the bullet jams .022 into the rifling. VLD's offer a lower drag due to less of a contact surface with the barrel. The problem with them is they end up being long and usually do not fit in the magazines.
Jumping the bullet is the most common practice with most manufactures, you tend to have lower pressures than you do if you Jam it or load it at the edge of the rifling. SMK's or SC have a larger barrel contact surface that aids in stabilizing the bullet that the VLD's don't have. So you can jump them.
I'm sure someone will punch holes in my attempt to explain this, o'well...
</div></div>I just finished developing a load for my 260. I tried SMK 142,123, Berger 140 VLD, Hornady 140 AMax and Lapua 139. The Lapua was by far the most accurate in my rifle. .26 MOA vs. .75 MOA. I found that setting the Lapua back about .030 worked best for me. Jamming the bullets .005 or .010 gave a little less accuracy but the thing that I really did not like was that my SD and ES went up significantly when the bullets just touched the lands or was jammed up to .010. It got a little more consistant at .020 jam but not as good as backing off the lands.
Also note that Sierra has two style match kings, at least in 6.5mm they do. The 140 and 120 are more conventional and the 142 and 123 are VLD.