Don't give up on the 7mm-08. I bought my 7-08 a couple of years ago, and couldn't get it sighted in, I had other toys to play with so I put it away, then tried again the following year when I had nothing to do. Same problem, finally I decided that I was going to get the rifle sighted in. Went thru all the problem areas, checked the scope base, rings, etc.. Continued to have the same problem. I finally changed the scope like 44 man did, but still had the same problem, turns out, the first scope was bad, and the second scope, a scope of known reliability went bad. Who would have thought that would happen. After I put a new scope on it, added an O-ring, and finally got it zeroed. That was also after, I changed the synthetic fore end to a wood one which fit looser. Now I have a strange looking rifle, schnabel wood (brown) fore-end, black synthetic stock, cheap Simmons 8 Point scope, but she shoots.
BTW I sighted in using factory Remington 140gr PSP ammo, for some reason, my 7-08 didn't like the Federal 150gr Classic loading.