Generally, any rifle should have its bore slugged, unless of recent manufacture and even then, slugging doesn't hurt. Most 6.5x70Rs would take .260-1" bullets and 6.5x55 bullets would not be appropriate, unless resized. On the outside chance one is reported to have been made for a .264" bullet, I would want to verify that myself. We often use a test for 8mm rifles that may result in larger than normal bullets. Due to my experience with similar 6.5x48R and 6.5x58R cartridges, I cannot advise using this test or use it myself for these cartridges. Being from the old school, I still hold my cases for annealing in my bare fingers. For normal cases, I cannot hold one long enough to "burn" it. The 6.5x70R, however is longer than normal and it may be possible to hold it long enough. In recent years, different machines have been made that allow inexperienced shooters to properly anneal cases. If I were just starting, I think I would either buy or make one of these machines.
Mike
