RE: Heavy Barrel
I'm a fourth gunsmith and I can tell you that the other responses are partially true.
Heavy barrels do help with the harmonics but it doesn't dampen them, it is more rigid so there is less harmonics. The heavy barrel also DOES NOT dissapate heat, it does the opposite. DO NOT fire a bunch of shots back to back out of a heavy barrel unless you want to loose accuracy and wind up replacing the barrel in a couple of years, it will distort the barrel, not to mention that it heats up the riflings which makes them softer and they burn out (become smooth) more easily. With a heavy barrel you should allow atleast 3 minutes between shots to allow the barrel to cool a few degrees and you don't ruin a good barrel. The weight of the barrel also helps you steady the rifle for more precise shots. If you want to improve your accuracy with this rifle there are two other things you can do. I suggest taking it to a gunsmith for these things:
#1. Glass bedding
#2. Recessed crowning (that is on the end of the barrel - if it has a scooped out look on the end)
#3. Reloaded ammunition - ask for accuracy loads or efficientcy loads, both are good an 3 times more accurate than factory ammunition.
Hope that helps.