Checking Mosin Nagant Headspace 7.62x54R.

This video shows how to check the headspace on a Mosin Nagant 91/30 rifle. The 7.62x54R cartridge has a rim. The headspace gauges have rims of different thicknesses. The go gauge is only slightly thicker than a cartridge rim. Too much headspace is a danger. The video shows the gauges and how to remove the extractor from the bolt head so the gauges can be used correctly.

[@leokimvideo]

Great insight into why these gauges are important. I did read up a wiki page on 'headspace' and I feel this explains what happens when the headspace is excessive. I've watched a lot of so called 'gun experts' on KZbin and none detail the dangers of poor headspace. From Wiki - In chamber designs that don't fully support the case head, it can allow a case to expand excessively, which can thin or even burst the brass. Thus the cartridge can rupture rearward, which risks releasing hot gases under high pressure that can damage the firearm and injure or even kill the shooter or bystanders.

[@ozzistraightshooter9273]

Thank you for your very informative comment

[@jamespollard1670]

Good stuff . I never understood the need for a go gauge . The factory ammo is the go gauge . I can see the go gauge as useful when installing a new barrel .

[@ozzistraightshooter9273]

Factory ammo can generally be acceptable as the go gauge but the actual rim thickness can vary by as much as 0.25mm and still be within specs. 7.62x54R ammo has been made over so many years and in so many factories there can be variations depending on the brand of cartridge case you choose. Often you can buy the gauges as a set so if you get the set it will be the best option.

[@andreasbrandstetter9221]

37 thousands of an inch😂 you now you know why we have metric.😂 Simply 1.6 times the small mm unit. So 1.6mm ....compared to37/1000 th of a weird inch which is 2.54mm.... oh man. Calculating and converting units in the us is difficult. How many cubic inches do you need for 1 gallon? 😂😂

[@philliplabbe4409]

jesus! This video could have been like ten seconds long. Get on with it!!