How to Check the Headspace on a Mosin Nagant 91/30 With Clymer Headspace Gauges
- 1). Open the bolt and retract it. Inspect the chamber to ensure no live rounds are in the chamber. Pull the trigger and remove the bolt from the action.
- 2). Hold the bolt in one hand, then pull back on the cocking knob and rotate it counterclockwise.
- 3). Pull the bolt head forward off the bolt body. Remove the extractor from the hold head by sliding it out of its dovetail groove. Use the plastic hammer and brass punch to tap it out if it does not move by hand.
- 4). Reassemble the bolt without the extractor. Insert the bolt into the action, but keep the action open.
- 5). Place the "Go" gauge in the action and slowly close the bolt. It should close with ease. Open the bolt and remove the "Go" gauge.
- 6). Place the "No-Go" gauge in the action; slowly push the bolt forward and gently start to close the bolt. The bolt handle should start to move, then stop. If the bolt closes easily, the chamber has excessive head space and is not safe to fire.
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