Don't make your decision based totaly on ES numbers. My main "deal" is shooting 1000 benchrest....and in 1K, I was told, ES is EVERYTHING!!!! I'm here to tell you it is not......long range group size and shape is king. It is all that matters!! My LG at this years IBS nationals was horse sh^% comparied to most of what I am used to as far as ES goes. The result....
The moral of this story is don't place to high a standard on ES.
H or IMR 4831 is to fast, in my opinion, for the 7mm rem, and I think maybe in everyones opinion with the 7 STW with the heavyer bullets. Like I have said before on other threads...I have been in love with the H1000/7mm/big bullet combination since thay came out with H1000. I have been a RL 25 lover in the 300 WBY with big bullets since RL 25 came out. I was messing with my dads origonal, factory, 24" bbled 7mm rem mag from the early 60's and 180 JLK's and tried RL25.....wow. I then tried My brothers custom 7mm with a 26" Hart....wow again!!! Silly speed with silly accuracy.
I would imagin with the STW that H1000, RL 22-25, Retumbo, and maybe a few that slip my mind would be awsome with the 168/180 class bullets. Big boilers love big bullets and slow powders!!!
Now, in 1000 yard comp. I will give up MASSIVE amounts of speed for extream accuracy. My very first comp BBL was a 300 wby. It had two very accurate loads....74 gr rl 25 and 82 grains of rl25....the difference....... about 2" at 1000 yards. That is HUGE....HUGE in 1K comp.....Result....3rd overall in The IBS SOY points race and rookie of the year. To a deer, we are talking an extra inch from center. Nothing.....Take the speed. Sure...if we are talking 1" 300 yard groups vs 4" 300 yard groups it is a no brainer...take the accuracy rout!! I guess what I am saying here is pick a burn rate that gets you the most speed and start your search for accuracy there. Don't try and re-invent the wheel by trying non standard powders...sure, you might stumble upon something, but more likely than not, you will find the answer with the proper burn rate. With the STW and big/bigger bullets, that is powder in the s...l...o...w catigory!!
This is the FUN part.....the load development....the bench time.....time at the loading bench...It's all good.....BIG FUN!!
Good luck...I was just re reading my post, and you know what.....I sure am a long winded SOB!!!