Jerry,
Who made your barrel? From what I understand, unless it is a higher end custom barrel (Krieger, Lilja, Shilen, etc) it hasn't been stress relieved and it will BENEFIT from having a pressure point of a few pounds located at the tip of the fore end.
You can test this out by cutting up 3x5 note cards (or manilla folders) into small strips and placing successive cards under the barrel and see if that solves the stringing problem.
I free floated a Ruger 30-06 thinking I was going to make and improvement. It still shot well, but no better. I had it glass bedded, and the gunsmith took out my free float job with a dab of epoxy close to the fore end. It shoots 3/4 inch groups all day. If you haven't done it, judicious bedding might take care of the stringing as well.
Also, after I clean my rifles, I always put a lightly oiled patch through the bore. But, before I go shoot, I put a dry patch through the bore and then a patch with a little windex (ammonia) through the bore to clean out any oil. I find the first shot is much closer to the following shots that way.
Is the stringing happening as the shots progress or are they random flyers?
Good luck!
