Go/no go advice
- Thread starter muleman69
- Start date
Well when I fit a barrel on my actions I use the go gauge and make a fairly snug fit with it on closing the bolt.
Then when I put the no-go in, the bolt should be just short of closing, but will not lock down.
From that point on I form and keep the brass fired in that chamber for that firearm only, sizing and working my brass/reloads to fit it.
Then when I put the no-go in, the bolt should be just short of closing, but will not lock down.
From that point on I form and keep the brass fired in that chamber for that firearm only, sizing and working my brass/reloads to fit it.
The no go gauge is the maximum SAAMI chamber length. If you have a paper punch, put a single piece of chad between the bolt face and the go gauge and screw the barrel in until you just start to feel resistance. Snug up the barrel nut and then insert the no go gauge and check to verify that the bolt doesn't quite close. You may have to do this several times. This should set the chamber length .002-.003 shorter than the SAAMI max. It will also cycle most any factory ammo out there.
Pacific Tool and Gauge offers three lengths of headspace gauges per rifle caliber. In order from the shortest to longest, they are: GO, NO-GO, and FIELD:
- GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gauge, the chamber will accept ammunition that is made to SAAMI’s maximum specifications. The GO gauge is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gauge is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser.
- NO-GO: Corresponds to the maximum headspace Forster recommends for gunsmiths chambering new, bolt action rifles. This is NOT a SAAMI-maximum measurement. If a rifle closes on a NO-GO gauge, it may still be within SAAMI specifications or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gauge. The NO-GO gauge is a valuable tool for checking a newly-reamed chamber in order to ensure a tight and accurate chamber.
- FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gauge, its chamber is dangerously close to, or longer than, SAAMI’s specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gauges are slightly shorter than the SAAMI maximum in order to give a small safety margin.
muleman69
USMC -1st marine Div. RVN
I was thinking of sticking a piece of scotch tape on the gauge and see what that gave me for clearance. Might be to much but I will mic it first and see what I get.
That's how I set my headspace as I learned that method right hear on the forums long time ago!
I buy a go-gauge only and set the headspace...then put a piece of scotch tape on the back of the go-gauge then if the bolt does not close your headspace should be about perfect as seems when I measured the scotch tape my headspace was within about 2 thousands clearance.
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NorCalMikie
Gold $$ Contributor
SAAMI specs have a lot of slop in them. I set all my head spaces on the snug side. That way, you move the brass less when resizing.
Less movement=longer brass life.
Less movement=longer brass life.
Coyotefurharvester
Silver $$ Contributor
Go + 0.002
At the Savage Shooters reloading forum you read all the time about someone using a new unfired case and scotch tape to set their headspace. Their next posting is "Help my resizi ngdie won't push my shoulder back" and they can't close there bolt on a resized case.
The problem is you have to deal with chamber diameter and headspace and the ability of the die to push the case shoulder back shorter than the go gauge.
You can set your headspace as snug as a GO gauge or even tighter, "BUT" depending on your resizing die you "might" end up lapping your shell holder for enough bump.
Bottom line, scotch tape can vary in thickness and chambers and dies vary in size. And the distance between the GO and NO-GO gauge is wiggle room for setting up new and rebarreled rifles. And the .006 to .007 between the NO-GO and Field gauges is still allowable headspace.
So food for thought, whats wrong with a little wiggle room when brass spring back after sizing "might" cause a chambering problem.
Most American made cases are shorter than the GO gauge, but the SAAMI cartridge and chamber drawings show case manufacturing tolerances .004 longer than the GO gauge.
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6MMsteve
Gold $$ Contributor
trouble free headspace for me is just a little bit of feel on the go gauge ...and I'm done...of course with the inerds out of the bolt....in a savage...since I been doin this my brass is just so cozy... but use the no go gauge if you not use to doing it....and that way your safe but .004 is a bunch in chamber shoulder talk
Use the go,save the money for a no-go,use brass shim stock .001--.002 on back of the go gage,or use piece of yellow page from phone book,they are normally .002,it doesn't take very long to cut to fit back of go--gage,Minimum Headspace,usually More Accurate,less case stretching,less shoulder bump needed to resize
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