...39 gr Sierra on 24.5 grains of RL10 3700 FPS factory OAL.
I looked at Lyman's 49th for a reference and got 40grV-Max/23.3gr RL-10 at 56,000psi.
Alliant didn't list RL-10 for the 204, and Sierra didn't have anything for me in their 5th ed either. So I went looking on the web... found loads as high as 25.1gr under a 39gr BlitzKing
, I ran QuickLoad at your 24.5gr under a the 39gr Sierra and got 66,000 psi. (The Case max is 58.7).
Any chance you're stressing things a bit?