I wonder if a bigger draw (or at least a factor) in going to the AI version is the cool looking improved case. I know I like looking at the .257 AI more than the .257 Roberts. It's like comparing Pamela Anderson to Kate Moss...

I too have found the Nosler loads to be very conservative. I am getting 3080fps with the 117gr. Hornady SST with 53gr. RL22 in my 257 AI. (24" barrel). I tried the listed loads in the Nosler manual and found that their max loads were 2-4grs. lower than I got in my rifle. I also own a 30-06 Ack. The Nosler Manual lists a max load for the 30-06 Ackley at 62gr. of RL22 (180gr). The load listed for the standard 06' is 61gr. I am loading 64gr. of RL22 in my rifle and there isn't any hint of pressure signs. I'm getting just over 2900fps. (24" barrel) with the 180gr. Hornady or Speer Grand Slam.
Elk Country

i just don't understand why a 257 ai will produce any great increase in velosity, when i load 45gr of 4350 in a normal rberts if fills less than 85% of the available case with a 120 gr partation.. you can shake the case & listen to the powder move. I have loaded with out pressure signs 48.5gr of rl22 & got 3025 fps in a 22" bbl. In reality the Roberts is a wildcat with factory cases because it is so underloaded both factory & reloading manuels.. By the way my 257 roberts load is 45.0gr of h4350 with 120gr partations at 2850fps..