Jerry,
I tried as far as powders go, N165, H4831, H1000 and Retumbo. My target speed was 2950. I was using 210 primers and finding no pressure. The first barrel had just over 600 rounds through when I decided to go to a 600 yard match in Dec. 2005. I loaded up enough rounds on already fire formed cases and went to the match. I asked a friend to watch where my first shot went as I was coming up from a 200 yard zero from the day before. I added 10 minutes to the scope and watched the vapor trail draw a straight line to the target with what seemd no arc. It got there a whole lot faster than 2950. I didn't shoot anything smaller than 6 inches that day. Not very good. A couple of days later I started looking into what was causing the high speed that I chronographed, ( over 3200 fps), and found that I could not seat the bullet out far enough to touch the lands.
The following weekend I took the gun down to Clay Spencer to get him to rebarrel the gun. We bore scoped the gun and found that the throat was eroded over 8 inches.
We decided that a new barrel was in order, DUH! Also, found that my existing reamer was not in the best of shape after being used once. The previous smith had somehow put a bend in it or it was defective from the get go. I don't know which. But we ordered another from Dave Kiff and Clay installed another barrel after doing a couple of other things to the reciever.
When I got the gun back, I quickly found a load that shot to my satisfaction and proceeded to shoot the gun in the matches. When the time came to get ready for the 2006 World Open in Pa., I rechecked the seating depth and found that I had to extend the seater out in the die to where I had one thread left before it came out of the die. My round count at that point was just under 450 rounds. Myself and another shooter shot the gun, competitively that weekend, but I spoke with other guys shooting the same cartridge, and found that I was not the only one with the same conclusion. One guy told me that he set his barrel back evry 400 rounds.
I went back to Clay the following week and he ask me what was wrong with the gun, and I told him that it needed a bigger hole down the barrel. The gun has been a 300 WSM ever since. I have a HG in 300 WSM that had over 4500 rounds on the barrel and was still very competitive when I told Clay to put another barrel on that.
In closing, it is my determination that the 7mm WSM is very overbore. If I had the money and time, I would shorten the case, and try again, but the 7mm Rem Mag is doing all I want with the 180 Berger, except I would like to see 2000+ rounds out of the barrel before replacement, instead of around 1200.
I get well over 2200 out of my 300 Win Mags, and I am very happy with the 300 WSM.
And, no I have never tried the 284 Win. case, but I do not see why it won't work.
I feel that as tight as money is these days, you need to get all you can out of the various components that we use in this game.
Sorry to be so long winded, but I studied this for a while because of my ultimate dissapointment in the case, after having very high hopes.
On the other side I have some very nice dies and a reamer for sale cheap
Danny