Tagged for interest. Working on a 204 myself.
it will probably be a couple of weeks before I start testing the 40 grainers. I am working on a .308 tactical build for 600 yards right now but here is what I had on DVD from when I was doing load workups for the .204 with the RL 10 a few years back. The TAC and Varget data disappeared when my laptop bit the big one. The gun is a Stevens 200 action rescued from a pawn shop then put in a Choate stock, added a Timney trigger and Criterion 26 inch SS 1 - 11 with a varmint taper. It shoots consistent .5 groups out to 200 and if it is a calm or on the rare day when my wind/mirage skill is working can go out to 300 and shoot sub MOA.
Currently the action and barrel are on a MDT LSS chassis and the .308 is in the Choate, I have not shot it since changing stocks
As usual the disclaimer to start with the powder manufacturers load data and the minimum charge.
http://imgur.com/a/qV3vj
sorry about the dupe images, this was my first time using this photo hosting service
Range report Jan 01 2013 60F 0 wind @ 100 yards
All Groups measured Center to Center rounded to nearest tenth
Target A all 39 Gr Sierra's
1) 3 fowlers
2) 23.7 RL10x 2.280 OAL 3650 FPS SD 29 FPS .5 group
2A) 23.7 RL10x 2.275 OAL 3650 FPS SD 17 FPS 3 shots .3 group
3) 23.7 RL10x 2.275 OAL 3650 FPS SD 15 FPS .5 group
Target B
1) 5 cold bore shot 39 Sierra 23.7 2.260 OAL
2) 39 gr 23.7 RL10x 2.260 OAL 3650 FPS SD26 FPS .7 group
cleaned rifle
4) 5 cold bore clean bore shot 39 Sierra .75 group
34 grain dogtowns seated to 2.00 OAL which is .35 off lands
5) 22.0 RL10x 2.00 OAL 3637 FPS SD 65 FPS .6 group
6) 22.5 RL10x 2.00 OAL 3721 FPS SD 18FPS 2 inch group with one a inch to the right and another 2 inches low
7) 22.7 RL10x 2.00 OAL 3735 FPS SD 22 FPS .5 group
9) 23.0 RL10x 2.00 OAL 3754 FPS SD 34 FPS .5 group 4 were in .2 range with one flyer
Target C
1) cold bore shot
2) 23.2 RL10x 2.00 OAL 3757 FPS SD 88 FPS .8 group
3) 23.4 RL10x 2.00 OAL 3764 FPS SD 94 FPS .9 group
4) 23.6 RL10x 2.00 OAL 3774 FPS SD22 FPS .7 group
5) 23.8 RL10X 2.00 OAL 3842 FPS SD85 FPS 1.0 group
6) 24.0 RL10x 2.00 OAL 3875 FPS SD 22 FPS .3 group
7) 24.2 RL10z 2.00 OAL 3878 FPS SD 22 FPS .8 FPS
bolt seemed sticky around 23.6 and up but no pressure signs on primers. All primers were CCI 450 small rifle magnums. Gun seems to like jump of .35 off lands