My 204 is a Remington VSSf II with a 26" barrel.I load Winchester Cases with Varget powder and CCI bench rest primers and use Sierra 39 gr Blitz King bullets. This load will give me consistent 1/2" to 3/4" groups at 200 yrds with no wind .My trigger has been lightened to 1-1/2 lbs and the flash holes have been DeBured and the primer pockets uniformed.This is a very accurate load as I have passed this load on to 2 of my buddies and they BOTH shoot under one inch at 100 yds.Here is a link for some good 204 info.
http://www.rugerhunting.com/
Just to advise you my chronographed velocity is 3690 fps.Work up your loads slowly as groups were good to start with but got better as I shot couple hundred rounds through it ,got the brass fire formed and neck sized,
Good Luck,Hope this load works for you!