If you’re still finding your way around your rifle, you may want to know what ‘head space’ is. Aki Suvilahti from Sako Cartridges explains.
“Head space is a measure, in the rifle, from bolt face to chamber. It is in the part of the chamber that stops the cartridge’s forward movement,” he says. “So this measure can be different in different calibre rounds. For example with the .375H&H, which is a belted rim cartridge, the headspace is from the bolt face to the front part of the belt, so it’s considerably shorter than in the .308 Win, which is from the bolt face to the middle of the shoulder.”
And that’s important when it comes to pressure. “It has to be in correct limits,” Aki adds. “So let’s say if the headspace is too short the cartridge doesn’t chamber at all or very hardly and if it’s too long it can break the case very easily. It has to be correct.”