Belted go and no go gauges

[Victor3Ranger1]

I would like to be educated on go and no go gauges.
I see that the go gauge is .220
The field gauge is .227
And the no go is .235??

Can you guys teach me about setting up the headspace with these?

 

[MagnumManiac]

Belted gauges are simple, headspace to .220" when cutting with the finish reamer and that's it. More headspace than this WILL cause issues, especially swelling above the web. I err on +/- .002", but with my set-up I could keep all chambers within .001" of each other.
I had a factory rifle once that had .008" too much headspace on a 300WM, just enough that the no-go gauge wouldn't close, but the go gauge was loose. 3 firings of ANY brass and it fell in half.
I am very pedantic about belted magnum headspace because, even though uncommon, brass can vary considerably in datum from .220", which is what it should be…

Cheers.

 

[Victor3Ranger1]

I have an old savage 110 that I am putting the barrel back on the action and when I torqued the barrel back on it is further in almost a 1/4 of full revolution.
Can I use the go gauge and tape to somehow confirm just how much headspace I have?

 

[MagnumManiac]

Only if you know how to measure precisely to .0001" on all required dimensions, tape will crush and change measurements.
The amount it screws in further should not matter as long as the bolt doesn't close on the no-go gauge. I never use the field gauge either btw.

Cheers.

 

[Victor3Ranger1]

I had never heard of the field gauge before

 

[MagnumManiac]

I had never heard of the field gauge before

It is a military thing used by some to determine how bad a chamber is, it really isn't needed.

Cheers.

 

[biednick]

I had never heard of the field gauge before

They're the maximum headspace dimension. If a gun closes on a field gauge it's out of spec. We typically use a no go gauge, which falls in the middle of the headspace tolerance, instead of a field gauge. It's possible to have a gun with an in spec (though loose) chamber that will close on a no go gauge.

There's either an error with the numbers in your post or the manufacturer is using different terminology than the rest of the industry.

 

[Tiny Tim]

If I'm not mistaken, different manufacturer's have different specs on their no go gauges. One may be .004" over go, another may be .006".

 

[HandgunHTR]

Are you sure that the no-go isn't 0.225" rather than 0.235"?

In most cases the maximum allowable headspace is whatever the minimum dimension is +0.010". The gauges are usually setup such that the go-gauge is minimum headspace. The no-go is +0.005 of minimum, and the field is at the max of +0.010" of minimum.

 

[FEENIX]

I had never heard of the field gauge before

I use Foster's go/no-go gauge. The field gauge is also available, but I did not purchase it.

If a rifle closes on a GO gauge, the rifle chamber will accept any ammunition made within SAAMI spec.

If a rifle closes on a NO-GO gauge, the rifle chamber might have excessive headspace. Most gunsmiths chamber a rifle's headspace between the GO and NO-GO dimensions.

If a rifle closes on a FIELD gauge, the rifle chamber is dangerously close to or already over the SAAMI-specified maximum chamber size.

(SOURCE: https://www.forsterproducts.com/product/rimmed-and-belted-headspace-gages/)

 

[Victor3Ranger1]

Thank you, that clears up a lot