I am a relative newbie to reloading and will soon begin reloading .308 Win for a Browning X-bolt. There is only one reloading aspect (so far) that confuses the heck out of me: HEADSPACE.
First, it is confusing because there are so many different definitions for it. Examples:
Definition 1: The fit of a cartridge in a chamber measured as the distance from the bolt face to that part of the chamber which stops the case’s forward movement (for .308, it’s the shoulder). Note: this is a measurement of the CHAMBER.
Definition 2: The distance from base of the cartridge case to that part of the case that stops its forward movement (for .308, it’s the datum point along the shoulder, .400 inches in diameter). Note: this is a measurement of the CARTRIDGE, not the chamber.
Definition 3: The distance between the bolt face and the datum. Note: this is a measurement of the chamber AND the cartridge, because the bolt face is one end of the chamber and the datum is on the cartridge.
All of these definitions are DIFFERENT. So do you see why I’m confused? Can anyone clear this up?
Second, I am confused because I don’t know WHY I need to worry about headspace anyway. I will not be reloading for competition, just informal target shooting and hunting. The best accuracy I expect to achieve is 1-inch groups or slightly less. I will pay attention to maximum cartridge OAL. I will be using a factory produced rifle (Browning) and factory produced dies (Lee). So, can anyone clarify why I need to worry about headspace, and how I would go about solving any “headspace problems”?
Thanks.
Greg
First, it is confusing because there are so many different definitions for it. Examples:
Definition 1: The fit of a cartridge in a chamber measured as the distance from the bolt face to that part of the chamber which stops the case’s forward movement (for .308, it’s the shoulder). Note: this is a measurement of the CHAMBER.
Definition 2: The distance from base of the cartridge case to that part of the case that stops its forward movement (for .308, it’s the datum point along the shoulder, .400 inches in diameter). Note: this is a measurement of the CARTRIDGE, not the chamber.
Definition 3: The distance between the bolt face and the datum. Note: this is a measurement of the chamber AND the cartridge, because the bolt face is one end of the chamber and the datum is on the cartridge.
All of these definitions are DIFFERENT. So do you see why I’m confused? Can anyone clear this up?
Second, I am confused because I don’t know WHY I need to worry about headspace anyway. I will not be reloading for competition, just informal target shooting and hunting. The best accuracy I expect to achieve is 1-inch groups or slightly less. I will pay attention to maximum cartridge OAL. I will be using a factory produced rifle (Browning) and factory produced dies (Lee). So, can anyone clarify why I need to worry about headspace, and how I would go about solving any “headspace problems”?
Thanks.
Greg