My build has a 5.56 chamber, my bolt is a Stag . I noticed while looking for gauges, they sell both 5.56 and 223. Do i need both, or just the 5.56? I'm assuming I'll be GTG with 223 if the 5.56 gauge is a go?
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Go no Go Gauges, what to buy?
- Thread starter rkwjunior
- Start date
The only guns I have headspaced are AKs, but I would say that you should get a set of go-no go gauges in the caliber that your chamber is stamped. If that is 5.56, then get those. I'm no expert, but from everything I have heard and read, it is not good practice to just check a new gun/barrel with a field gauge.
warwickben
bubba Kalashnikov
If you look at the specs you'll see there is a difference .
On the no go the 5.56 is .0036 bigger
Field gauge is 556 is .03 bigger.
Go gauge for mill is .0006 bigger also .
In reality it don't matter if you in that .0006 or .003 difference on head space you on the extrem ends of the Max .
I've used a .223 gauges to head space one of my aks with a 556 chamber
On the no go the 5.56 is .0036 bigger
Field gauge is 556 is .03 bigger.
Go gauge for mill is .0006 bigger also .
In reality it don't matter if you in that .0006 or .003 difference on head space you on the extrem ends of the Max .
I've used a .223 gauges to head space one of my aks with a 556 chamber
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Haha, well i saw almost 200 views and only 4 responses and about to go to the next page, so i panicked..
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Ok maybe i'm over thinking this, i'll just go with the 5.56 go no go. Thanx Ben.
The main differences in 223/556 chambers has to do with lead and free bore.
You have to remember in the early days of 223 rem it was a vArmint round and guys where shooting 36-52 grain bullets from their bolt guns. So when 556 M193 and then later M855 which is loaded to a higher pressure . What would happen then is when surplus mil spec ammo found its way to the civilian market the 556 FMJ ogive would cram into the lands of the bolt guns and cause a very high pressure in the chamber.
If you look up the specs of each chamber and manufacture of gauges they will varry.
Headspace is not a huge "difference" in terms of safety between 223 rem SAAMI spec and 5.56 NATO.
If your bolt closes on a go gauge it's ok if it closes on a no go you have problems.
A field gauge is only needed if your gun closes on a no go. Also field gauge is just as it is named. Used in the field like a remote depot doing weapons inspection. Slap field gauge in if it passes gun goes back out. If it fails gun is taken out of field use to be repaired/rebarreled later.
You have to remember in the early days of 223 rem it was a vArmint round and guys where shooting 36-52 grain bullets from their bolt guns. So when 556 M193 and then later M855 which is loaded to a higher pressure . What would happen then is when surplus mil spec ammo found its way to the civilian market the 556 FMJ ogive would cram into the lands of the bolt guns and cause a very high pressure in the chamber.
If you look up the specs of each chamber and manufacture of gauges they will varry.
Headspace is not a huge "difference" in terms of safety between 223 rem SAAMI spec and 5.56 NATO.
If your bolt closes on a go gauge it's ok if it closes on a no go you have problems.
A field gauge is only needed if your gun closes on a no go. Also field gauge is just as it is named. Used in the field like a remote depot doing weapons inspection. Slap field gauge in if it passes gun goes back out. If it fails gun is taken out of field use to be repaired/rebarreled later.
Any budget/economy versions of these gauges?
warwickben
bubba Kalashnikov
Not some thing you want to cheap out on.
1903Collector
NES Member
Only thing I'll add is don't mix and match manufacturers if you buy a set. I know people who have done this.
Jasons in post 14 had right data.
After a lot of research and study, I concluded that for an AR15 in 5.56 Nato or Wylde chamber I would do the following ( look at the data and make your own decision)
For a new barrel / BCG combination the headspace range is 1.4646 (go) to 1.4706 (no go). All I have tested have fallen in this range.
For a used barrel / BGC combination if it accepts the no go, you can check it with the Colt Field II (1.4736). If it accepts the Colt Field II it is UNSAFE to fire.
I bought and use Clymer go and no go gauges that are labeled 5.56 Nato GO and 5.56 Nato NO - GO that have the above measurements, and have the Foster Colt Field II. I have yet to find a rifle that accepted the No-Go gauge, so have never used the Colt Field II. I think if I had a rifle that accepted the NO-GO gauge, I would test with Colt II field gauge for kicks, but would fix the issue rather than attempt to use it.
You also have to use the gauges in right way to get accurate results.
When I was doing a lot of Mil Surp stuff, I had foster gauges in '06, M1 carbine, 308 that I used (gave away the M1carbine set recently). But I see no difference in Clymer gauge usability vs foster. Twice on garands had them accept no-go gauge, one of which accepted the Field Gauge. Both were private sales in early 80's and I did not buy either.
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1903Collector
NES Member
And too confuse the matter even more I have had bolt/barrel combinations close on a no-go from one manufacturer but not another ![[thinking]](/xen/styles/default/xenforo/smilies.vb/010.gif "Thinking [thinking]")
There are more expensive ones I'm sure. 60$ seems reasonable especially if you use them more than once. Or you can sell them when your done on EBay.
Not sure why you would want cheap tools to check headspace. If the gun is a cheap build you can do a cheap HS check.
Chamber round and shoot it.
And too confuse the matter even more I have had bolt/barrel combinations close on a no-go from one manufacturer but not another
Want to get even more confused look at the maximum case headspace.
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