Where it leaves you depends on a few other things.
The case is supposed to headspace on the belt. There's only .003-inch spread between GO and NO-GO headspace gages for H&H belted cases. It's been my experience that such belted cases produce best consistant accuracy if the shoulder is set back at least .005-inch but not more than .010-inch to ensure the case headspaces on that belt. Case life will be shortened somewhat by doing this but accuracy sure improves.
If your cases have a tiny step in front of the belt where the body (or full-length) sizing die stops reducing fired case diameter, that step may interfere with the chamber at the same place when the cartridge is loaded. That interference can cause accuracy problems. When I use cases with that step in them, they don't shoot as accurate as new H&H belt type cases. Many other folks notice the same thing.
Few if any body or full-length sizing dies reduce fired case diameter immediately in front of the belt enough to eliminate that step. There's a collet die from www.larrywillis.com
that does the trick perfectly. And it'll work on most other H&H type of belted cases.
It's been my observation that belted cases shoot most accurate when all of their body diameters are resized back to almost their original dimensions except for neck diameters which can be adjusted for tension on the bullet. Shoulders should be set back enough to ensure the case headspaces on the belt and not the shoulder.