So, one thing I've learnt so far is that bullets vary in their length quite a bit but there's really two readings to think about:

1. Cartridge overall length for magazine fit
2. Ogive measurement for seating depth

How do you you chaps know the correct seating depths when you're handloading and where do I start? Do I need to buy another specialist bit of kit to measure the ogive in relation to the lands and them work back bit by bit?