TIPS ON HEADSPACE - GAUGING SAFETY »

Headspace can be thought of as something like this: The cartridge in your chamber is in a safe with the bolt of the rifle as the door. That cartridge has to be held tightly by the door or the cartridge could rupture and allow the explosion to vent back out of that door with disastrous and dangerous results. Headspace gauges are used to determine how tight this lock-up is.

For each rifle that you want to check you must remove the bolt and COMPLETELY disassemble it. The stripped bolt must be able to enter the barrel breech with no resistance and the bolt face must contact the gauge properly or you will not be able to feel the lockup when you close the bolt on the gauge. Next clean out the chamber, being absolutely certain there is no powder residue, rust, oil or anything else in it that will prevent the gauge from properly seating in the chamber.

The chamber gauges are specific to the caliber of gun. Be certain you obtain and use the correct gauge for your various rifles. The gauges come in "Go", "No-Go" and "Field". The "Go" gauge is used primarily for fitting new barrels. You should only need the other two. Start by slipping the "No-Go" gauge into your chamber and then gently close the bolt on the gauge but DO NOT try to force the bolt handle down. Instead, ease the bolt handle down onto the gauge. It should NOT close completely. If the bolt does close completely remove the gauge and insert the "Field" gauge and try again. If the bolt closes completely on the "Field" gauge the gun may be unsafe to fire. If it does not close completely it is presumed safe to fire, however accuracy may suffer and the rifle should be considered ready to retire.

Just remember to play it safe. If the gun is marginal it's best to hang it on the wall in a place of honor and use something else.