09-28-2011, 04:59 PM
LRRPF52 Wrote:Joe,
That's funny that you mention .260 Rem versus .270 Winchester. I recently purchased two different projectile types for my .270, since there are match pills available now from Sierra and Berger. Sierra makes the .277 135 SMK, and Berger makes the .277 130 and 140 Hunting VLD's. I got the 140 Bergers, and ran both G1 and G7 forms through Berger's ballistic program. The .270 needs at least 250fps more MV to match the .260 pushing the 6.5mm 140gr Berger VLD, but the 6.5 has quite a bit less wind drift at 1000 yards.
That being said, if you really push the .270 to 3000 fps and faster, you can get under 8 Mils of elevation for 1000 yard impact, which is pretty nice, but I can do that with the .260 Rem and much less velocity, like I said. You can tell which is the superior caliber for aerodynamics by just looking at the 6.5's versus .277's. The .260 starts to deliver more muzzle energy and flatter trajectory at 500 yards when comparing the 140 Berger VLD's in 6.5 and .277. It takes around 60 grains or more of powder for the .270 to launch at those velocities, and a long action as well. At least I have some use for the H4831 powder I bought now in a case that can suck it up. The .270's attraction is that it delivers more mass per area of impact, so it will probably ring steel nicely. I'll see soon enough!
We are getting nearly 3200fps on a 130 SST with awesome groups. The Remington 760 is a slick old gun if you know how to tweak it just right. Plus you do not have to break your cheek weld while firing and tracking for another shot is needed.