I received a RCBS Precision Mic for my 325WSM. This is one of the best tools for reloading I've found. Within minutes I was able to measure the headspace on both my WSMs and check my brass that was ready to reload. I can now make my brass last longer by preventing overworking it. Also makes setting up your dies a snap. Great product.
I also bought a new box of factory ammo for my 270WSM, the extractor was having a hard time locking on to them. I measured them in the tool and found them .006 shorter than SAAMI specs.
1. Measures shoulder to base of shell
2. Measures the freebore of your rifle
3. Measures ogive of seated bullets.
Using these 3 measurements, a handloader can manufacture a more precise round for any given rifle.