Have you ever measured more than one GO gauge for the same caliber?

[carlsbad]

I usually make my own and they match my drawing. That said, They are pretty much arbitrary unless you're setting up a rifle to shoot factory ammo. Now the difference between go and no-go is nominally .004 and that's too wide if you want all your rifles to be the same. Many of us stay at one end or the other for consistency (for example, I don't want to have to adjust shoulder bump between rifles). So if you're chambering right at the short end and the next gauge is .0005 longer, it may not close.

--Jerry

 

[Alex Wheeler]

If some one is using a field gauge, more than likely we are talking mil surp and a very likely reason the bolt is now closing on a field gauge is lug set back which will increase unsupported case as Tobnpr mentioned.

 

[tobnpr]

No he said the thinner brass in front of the casehead being unsupported. If he meant stretching then yes

Exactly what I meant.
Field gauges were designed to indicate when lug wear/setback on military rifles had gotten to the point of being dangerous and the rifle was to be removed from service. The case will stretch until it contacts the boltface.

 

[Canadian bushman]

My customer barrels are alway saami gauge +.002/+.003 when torqued to 70ft/lbs

My personal barrels are chambered to my virgin brass and thrown away together. Usually i torque my barrels to 30-40ft/lbs with copperkote.

 

[a6mmbrman]

What Mr. Tooley said!!!!