If you load and have Vihtavuori powder I can get you in the ball park. Buffalo bore makes a 255 grain cast that runs at 950fps with the standard recoil spring. I don't know his powder type or amount.

A 230 grain gold dot with 7.5 grains of VV N350 runs at 915fps and using 8.0 grains it'll run 983fps.

A 265 grain beartooth with 8.0 grains of VV N350 runs 1,004fps while 8.5 grains runs out at 1,061fps.