I quick tested the 100 gr E-Tip in my M700 Classic 257 Roberts and can share the following data with everyone.
IMR 4350 loaded to a Max charge with 41.5 grs, R-P case and Federal GM210M primers. Avg MV 2779 fps, ES 40, SD 20. Accuracy was 2.05".
RL 19 loaded to a Max charge with 46.0 grs gave an Avg MV 3053 fps, ES 38, SD 20. Accuracy was 1.772". The COL was 2.900" and I will have to work with this to improve accuracy.
I shot into water jugs at 100 yds, MV was 3042 fps and the bullet was recovered sticking out the back side of jug #5.
The recovered bullet weighed 98.7 grs and measured .584" diameter and the length is .635".
I will update with accuracy improvements.