Re: 264 mag vs 6.5x284
My experience in 6.5-284 load development is that most of them like 2950 fps +/- with 142 SMKs or 140 Bergers etc. I use 48.5 grains of H4350 to get that. My 264 mag could get them to 3200 fps with 65.0 grains of powder (say RE 25). So the difference is around 8.5% increase in velocity vs. a 34% increase in powder. Tradeoffs. Drop the 264 mag to the same velocity of 2950 fps and the powder required is something like 60 grains...24% increase.
The goals of the shooter come into play. Do you want bughole groups? The advantage would go to 6.5-284...Do you want flatter shooting? that advantage would go to the 264 mag.
Again, most of the high bc match bullets do not like to be pushed too hard. I have had strange results with the 264 mag pushing match bullets of 130 grains and above to high velocities. Drop balls, vaporization, 2 shots in same hole next one 5 inches out type thing.
Still, I really, really like the 264 mag Sendero with 120 grain ballistic tips at 3350 fps. Kenton knob, rocks for 760 yards please.
So my question is, why doesn't Remington wake up and make a 6.5-284 Sendero with an 8 or 8.5 twist?