New Ruger GP100 .357 6in Barrel

Today I traded my old third generation Smith And Wesson 6906 9mm for a Ruger GP100 .357 with a 6in barrel. I got a good deal on the trade in. Ran several rounds through in both .357 Mag and 38 Special. It seems at slow fire I am more accurate with the .357 loads. It will take several more rounds to get the trigger loose, the first 100 rounds it was very hard to pull the trigger and my shots were way of. Now the trigger is broke in a little and the shots are getting closer to the bullseye.