I recently finished my 338 edge build. It is a remington 700 action with 30 inch krieger 1-9.5 twist barrel. I have only tried 300 smk with RL25 . It will shoot very well but it is flattening primers bad with only 84.5 grains of powder. The velocity is around 2600-2650 with this load. It seems like this is pretty low compared to others. My oal is around 3.83. Trying to figure out how to get at least 2750-2850 out of it.
I would guess your resizing your cases to much and that would cause the flat primer maybe. As far as 84.5 grains of rl 25 you should be well under presure unless you have a very strange lot of powder. On Shawn carlocks web page he shows max at 91 grains and 2833 fps. If your bolt is not sticky I would keep going up in charge wieght.
Your overall length might be to long also. If they are touching the lands your going to get preasure sooner. Try 3.785 oal.
I think your cases are undersized. When you clean it do you get alot of powder fowling? When you shoot does it smoke? I can't imagine you are anywhere near max. I would keep going by half grains until the bolt gets stickey or you get to 91 gr. But the only way I would even bother with staying with rl 25 is if you have some really good reason too. I would switch to H1000 or retumbo and have a better temp sensitivity.
I wouldn't say there was excessive fouling. I am shooting through a suppressor so it would be hard to say if it was smoking. I went up to 85.5 and the bolt was sticky. I was just trying the RL25 because I have alot of it since that's what I run in my 408 cheytac. I have alot of Retumbo also I can try it. Do you think the H1000 is a better choice than Retumbo?