When you fire a new case,it headspaces on the belt and the case stretches from the belt, and can cause early case head seperation. You can resize after the first firing to just off the shoulder, or use a neck sizing die. Then you will be headspacing off the shoulder, and will get good case life and accuracy. If the case stretched alot(excessive headspace)on the first firing, case life can be short. My 300 Win. Mag. has a pretty tight chamber, and my Winchester brass lasts to 15 reloads, then the necks start to split. It all depends on your rifles chamber and your loading technique. [img]images/icons/wink.gif[/img]
yep, neck sizing is the way to go with a belted (or non belted) case. I use the Lee Collet die in my 300 Weatherby and have had excellent results.
What sometimes happens with hot loads and an "oversized" chamber is that the case just ahead of the belt grows to belt diameter. When this occurs, the case will not chamber properly and there is no way a reg. FL sizer die will squeeze down this area.
There is a company that sells a collet sizer to size just in front of the belt. Personally, my cases wear out in other areas long before the case gets "fat".
Weatherby cases are more likely to stretch then cases with a conventional shoulder. Watch your pressures and your cases will give you good life.
With proper sizing, a belted case is every bit as accurate as a non belted case. Just look at the 1000yd results.
Like Jerry said it's not possible to size the belt and just ahead of it like it is with a beltless so when psi is too high it can keep you from extracting it or rechambering the reloaded case in even a just a couple firings. Usually accuracy is just down from max psi anyway so it really isn't even an issue for me, but if I had a choice it would be beltless.