Very well could be, I'm not sure really. There's a couple of burn rate charts that don't exactly agree but what I noticed from the limited heavy bullet data I've seen is that 560 is usually closer to rl26 speeds than 565.I always thought that the n565 was closest to RL26.
But I can't find data specifically for the berger 170 using 565, so I went after the low hanging fruit first for hunting season (time is getting short). When I get more time I'll work up a 565 load.