Using 38 load data in a 357 case

[t0066jh]

I'm trying to develop a good load for shooting IDPA which requires a 125,000 power factor. I'm shooting a Model 19, 357 mag, 4" barrel, 158 LRNFP, 19 Brinnel rated. Can I use 38 load data in a 357 case to achieve.

1. Less recoil for better accuracy
2 Less fouling in the revolver.
3 Achieving the same accuracy with the 357 case as the 38 Special
4 Achieving the required Power Factor.

Any thoughts are appreciated.

Joe

 

[Steve C]

The small difference in the amount of case volume between the .38 spl and the .357 mag makes little difference in actual velocity with .38 spl level loads in the .357 mag. Your bullet is fairly hard though and if you lower the pressure of the round too much you may get bore leading.

As for accuracy and power factor that's going to be a result of trying several loads until you get one you are satisfied with.

I'd suggest using .38 spl +P level loads to start with if you want to achieve the power factor. You will need to chrono the loads to see what they're doing.