I used it in my 257 Roberts AI and as same load with 4350 showed some signs of pressure, R17 showed none what so ever! It shot really well, if I were home I could go to my reloading log and quote you the load data! The whole pretense about R17 was to give higher velocities, with lower pressures! It was in Handloader early this year the write up about it! I got starting load data from the factory online!
