Ok, I'm a rookie here and any advice is greatly appreciated. I've done a few searches on this topic and my reloading manual has a short explanation but I still come up a little befuddled. I understand all rifles are different and each has it's own distance to lands in the throat of the chamber. I have read that each gun has an optimum distance to which bullets are seated to give good accuracy. What tools would I need to find the best seating depth for my rifle and what is the proper way to check OAL on cartridges? Does case trim length play a big factor in seating depth and accuracy? Hoping a few veteran reloaders out there might enlighten me.