Explanation and use of Headspace Gages needed

[painter777]

Have tried my best to explain to a friend the use of the head space gages.
Could someone else chime in about the use of .30 cal No-Go...Go and Field Gages?
If he were to buy just one, which should be his first choice?

TIA,
Charlie-painter777

P.S. There Tim....read the responses for yourself.
Now you can decide for yourself .......

Information

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[browningautorifle]

I wouldn't want to separate the go-no go gauges. I would buy and use them together. The field gauge was for that very thing. I doubt any of us have to worry about battle emergency headspace with our surplus weapons.

[emmagee1917]

When putting a new bbl on a gun you have two problems with headspace to worry about --too little or too much. If the bolt will close on a "go" guage , then it will close on a round of ammo if that ammo is in specs. If it will not close on a "no-go", then the headspace falls in the proper range as to not cause a problem with factory spec'ed ammo. These are for newly assembled rifles. As they are shot , the headspace will , over time , increase as the reciever or bolt streaches or with wear/battering to the locking lug interfaces. This is normal and to be expected. It will reach a point where it will close on a "no go" gauge. This is , in itself , not dangerous and mearly notes a change is occuring. This is where the "field" guage comes into play. It is used to measure the headspace of rifles that have left the shop and been shot and been shot out in the field. When the wear has reached a point that the bolt will close on the field guage , it has reached the point where safety now becomes an issue.

Chris

[painter777]

Chris,
Thank you for helping me make a point to a rather hard headed friend.

Charlie-painter777