I feel for you as I too went through the same problems, I jumped on the berger bandwagon but I knew I was only interested in either 185's, 190's or 210 bergers. At 100 yards they shot great, I put alot of rounds through my gun, but once I moved out to 200 yards my groups went to hell. So then I tried other bullets, other powders, other primers, different seating depths and nothing was working and I was racking up my rounds down the barrel. Ok now lets go back about 6 months when I bought the gun brand new and took it straight to a gunsmith and had it worked over and a muzzle break put on. One of the things I kept blaming for my lousy groups was the trigger, so I bought a jewell, didn't help. Then another gunsmith told me to try barnes 180gr TTSX and for me to call his friend. Well because of the amount of rounds down the barrel it was felt the barrel was shot out. I took my gun to another smith and he took a look at the muzzle break and said it was built all wrong, there were some other things that I had done to the gun that were not right. We talked and agreed that the muzzle break was the biggest cause from the lousy acuracy from the gun. So he took the break off, yes now my gun does not have a muzzle break but I don't feel the recoil is nothing I can't handle. He also gave me a load to try and is suppose to be pretty deadly in the sendero 300RUM. To make a long story short I did take the gun out the other morning even thou it was colder then heck, I had to re-sight in my gun and then moved out to 200 yards and was pleasently suprised at the good groups, finally my gun was shooting the way it should. But I won't be able to do anymore shooting until I heal from my back surgery in January, so come April then I can start shooting to make sure. If I still can't get it to shoot any better then I will rebarrel it and have it rechambered to a 7MM STW. Good luck on your qwest for an acurate load.
Chuck