Has anyone found a .257 cal bullet with a BC over .5 G1?
I don't know why people claim .25-06 is better at range, when it's pretty clear there's higher BC bullets available in 6mm. At range, the velocity advantage of the .25-06 is lost due to wind resistance.
Basically splitting hairs but..
100 grain .25 interlock VS 100 grain .243 interlock
.25-06 has .6'' less drop, 2'' more wind drift, 20FPS slower impact speed and about 18ft/lbs less energy @ 400 yards. From there the 6mm will continue to outpace the .257cal because of it's BC.
That's just a flat based soft point BTW. If you used VLD's in the 6mm the difference in BC would become much greater, as I mentioned before there simply isn't a great selection of streamlined bullet in .25 cal, and I think that's where it's weakness lies. If there was better projectile selection for the .257 it would likely have the advantage at all ranges over the .243 win.
If we compare berger's 105 grain VLD in 6mm and their 115 grain in .257 cal (these bullet are roughly equally heavy for caliber)
.257 cal 3000FPS, G1 BC .466
.243 cal 2986FPS G1 BC .532
@400 yards
.257
19.3'' drop from a 200 yard zero
2230 impact velocity, 1104ft-lbs impact energy
12.5'' wind drift
.243
18.7'' drop from 200 yard zero
2306 impact velocity, 1240ft-lbs impact energy
10.9'' wind drift
With current projectiles on the market, the .243 has the edge. If .25-06's had faster twists and longer, more streamlined bullets it would have an advantage over the .243 win. Maybe it'll change in a few years. The .277 cal had the same problem when compared to .264/.284 cal. VLD selection was and still is fairly limited but not quite as limited as it was a few years ago.
For most purposes the game wont know the difference, which is why the cartridge's price and availability become the more important factors.
Oh, and just incase there's any doubt of the .243's performance at long range, I'll just leave this here, for those who haven't seen it.
https://www.youtube.com/watch?v=hY0w1c-gf18