Go and NO-GO Gauges

[KMAY]

Do i really need both the go and no go gauges? It seams like all you really need is the no go gauge and you can set head space from that?

[lwink]

I'm far from an expert, but what I've seen on here, elsewhere, and did myself twice so far was get a go guage only, then put a piece of scotch tape which is about .02" thick on the go guage base and it becomes a no go. I think if you are getting one or the other is would be more helpful and safer to get the go guage only.

[hotbrass]

Rebarreling a Savage is very simple and does not require anything more than a go gauge.

No Go gauges are useful if you are building a barrel because tolerance stacking can catch you by surprise even after careful measuring and cutting.

You might be surprised at how many factory new rifles will close on a no go gauge.

[KMAY]

So if i just order a go gauge for the 243 barrel and one for the 22-250 barrel i have i thats all i will need to set headspace?

[hotbrass]

I would say yes only IF you know how to set the headspace.

The .243 gauge will work for .243 Win, 7mm-08 Rem, .260 Rem, .308 Win, .338 Fed, and .358 Win also since the shoulder lenght, dia., and angle are the same. You might find a .308 go gauge is less expensive some places.

[usngunner]

My answer from this thread in April of 2008.

I guess it bears repeating as the cheap "let's save a nickel at the risk of our significant body parts" crowds are out again.

If you guys are that stupid and cheap, have a great time but don't post the pictures here later.

Look for the "Natural Selection" forums, the Child board is "Too Stupid to Live", and the subsection is "Hope they got it before they bred."

Do not skip the head space gauges, especially if it's your first time out. There are too many variables in setting head space on a fired cartridge. I really don't think that saving $34.00 is worth the risk. That's not being frugal, that is just cheap.

I know, "Big Gauge" is just ripping us off, but come on. ::)

My eyes, hands, and facial structures are worth more than that to me.

For the experienced members here, I'd honestly be careful recommending short cuts to people when you do not know their skill/experience levels. It's like having somebody stick their hand in a hot 440AC cabinet when you don't know if they know how to use a multimeter. Not really a good idea and one that is going to hurt somebody some day.

If you have been swapping barrels forever, by all means do what works for you, but a new shooter trying this out should really stick to the program and use the correct tools made to do the job. This isn't like swapping a 870 barrel, and bad things can happen.

At least that's my two cents on the matter.

[lwink]

Do what you are comfortable with, but I got my info/instruction for headspacing from what I thought was a fairly reputable source:

http://www.youtube.com/watch?v=KICBv-0U87Y

Sponsored by accurate shooter website and I assume since this guy owns the machinery he does and is apparently making a custom bench gun for someone else he would use a safe method of headspacing. Once again, I am far from an expert, in fact am just a beginner, but that is my .02 and what worked for me. Of course do what you are comfortable with and usgunner is right, this is not something where "close enough" is good enough, there are some serious side effects, from a broken gun to broken body parts if things aren't done properly.

[KMAY]

That is a nice video. I am going to just get the go gauge and put the tape over the end. That is a really good idea.

[sharpshooter]

Seems like everybody makes this harder than it needs to be. You can use a sized case or if you prefer, a go gauge and plastigage to check it. The plastigage will tell you EXACTLY how much clearance you have between the go gauge and the bolt face. Doing it by "feel" can be a judgement call.
Placing the go gauge in the chamber and screwing the barrel down to touch it puts it at zero clearance. Once you tighten the nut, the threads will tension and stretch to give about .002" clearance, but no more. That's where you want to be.
It's harder to get it wrong, than right.

[MikeCTX]

Have to agree with Fred, just changed the barrel out on my Mod 11 and it went so well figured I havd messed something up ;D. Used a single piece of tape on the go gauge bolt would not close - felt pretty good at that point - tape of bolt closed, tape back on bolt would not close. Had a no-go gauge on order already so when it arrived verified (bolt did not close here but stopped well short of the go gauge + tape).
Point here, is the go gauge and tape work - for the folks that have done a few (bunch for some) barrel changes can see that using a case would work - comes down to a little common sense and trusting what ya know. Now I'm ready to get another barrel and change the M12 out...

[JCalhoun]

I'm with Gunner on this one. The GO / NO-GO is the correct way to do it. Just make sure they are made by the same company. Clymer and JGS are good ones.

[axaviere]

if you just cant break off and buy a set, try this

http://www.reamerrentals.com/Product...%2D3000Sav%2Eg

you can rent one

[sha-ul]

as to head-spacing a rifle, wouldn't that depend partly on the intended purpose of said rife?
for a bench rest gun, that is almost always going to be very clean, & generally under favorable conditions, versus a hunting or military rifle where they may be used in rather UN-favorable conditions. I have heard tale of the use of a "set-to" go gauge. and in the youtube clip above He mentions that no go gauges are .004 over-sized. so he used scotch taped that mikes out to .002 head-space. would this result in a chamber too tight for hunting?

any military armorers here that can comment on what a mil-spec head-space is?

[laportecharlie]

The guy in the U-Tube video that Lwink posted is Gordy Gritters. He has built many winning benchrest rifles and does indeed know what he is doing.
Charlie

[BigDog]

I have only put 3 barrels on so far but the process that Sharpshooter described worked just fine for me. Use new brass that was sized with your dies for a custom fit to your rifle.

[Uncle Jack]

This recurring subject never ceases to amaze me.

People go out and buy rifles for $500 to $1000 and slap scopes ($200 to $1000) on top and then anguish over whether to spend $50 for a proper set of clambering gauges. How much did you spend for that custom barrel you want to swap?

Yes, you can follow the scotch tape school of gunsmithing, but remember there are no SAAMI specs for scotch tape. A couple of layers of various brands of transparent tape can vary as much as .002".

Yes, you can use a sized case to set headspace, but remember brass is an elastic material and depending upon the length of the cartridge it can "spring back" as much as .002".

Yes, you can probably use a properly trimmed popsickle stick, but remember wooden popsickle sticks can shrink and grow with the humidity.

Yes, I am a certified cranky obsessive compulsive Old Fart who has a drawer full of Go and No Go gauges

uj

[ande7824]

I did my first barrel swap with just the GO gauge. I put in the chamber, tightened the barrel down until it stopped, but did not "over turn it in". Then I cranked the nut tight. I measured the GO gauge with my micrometer, put one piece of tape on and measured it again, once in the same spot and once turned 90 degrees to be sure no major thickness variation. This got me to barely 0.002" more. I put another on and did the same thing, giving me a total of a shade under 0.004" (which I have read is around the NO-GO gauge difference, but this seemed to depend on the manufacturer). I slid it into the chamber and the bolt would not close. In fact the bolt handle was in the exact position as the one in the video demonstrating the tape technique.

DISCLAIMER: tape thicknesses can change, trust me, I know. I use and see alot of tape at 3M (work). SO PLEASE MEASURE BEFORE AND AFTER TAPE ADDITION!!!

[rjtfroggy]

Yes, I am a certified cranky obsessive compulsive Old Fart who has a drawer full of Go and No Go gauges
uj


UJ Here is an opportunity for a part time business for you, List all of those gauges and start a rental program. I'm sure with all the barrel swappers here you would do well, if you keep your rates reasonable.
Cash business-supplement retirement income= more $$$ for toys.

[Uncle Jack]

Yo, Froggy person;

I thank you for your thoughful suggestion, but I have no desire to supplement my retirement income. I revile in poverty.

uj

[319]

Do we have any documented cases of the tape method not working as advertised? I haven't done a search, but would be curious to find out how many times it has failed and if it was the method or operator error that caused the problem. The tape has worked extrememly well for the 3 barrel changes I have done so far. If a no go gets me .003-.004 and tape gets me .001-.003 I will take the tape any day.

[bigedp51]

The average unfired commercial cartridge case is .002 shorter than minimum head space for any rimless cartridge case to insure chambering. One piece of tape added to the rear of a unfired case "should" bring you to minimum head space and should be good enough for anyone.

I shoot and reload for the .303 British Enfield which at maximum military head space can have .016 head gap clearance or air space between the rear of the case and the bolt face.

You do not need head spaces gauges to set head space, all you need is a way to measure YOUR head space. A RCBS Precision Mic will tell you all you need to know and you can use it for resizing your cases and setting up your dies.

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5130-1.jpg[/img]

Below is "0" or minimum head space for a .308 Win.

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5157-1.jpg[/img]

Here is a fired .308 case in the RCBS Precision Mic and it is .001 longer than minimum head space.

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5155.jpg[/img]

Below is the same new unfired .308 ammunition in my gauge, and this means the case stretched .003 on firing

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5163.jpg[/img]

With the RCBS Precision Mic you can measure your cartridge without any tape and then add tape to the rear of your case and KNOW to the thousandths of an inch where your head space is set at.

All a head space gauge will tell you is if your bolt will close, the RCBS Precision Mic will tell you far more and unlike a head space gauge you can keep using the RCBS Precision Mic to check you cartridge head space and setting up your reloading dies.

You people are taking "head space" to the extreme, on my Enfield rifles I can replace the bolt head to change and decrease head space. On a worn out Enfield that fails head space and if it can't be fixed you slip a rubber o-ring around the case and fire form the cases at "zero" head space. Zero meaning the rubber o-ring holds the cartridge case firmly against the bolt face and you DO NOT get any case stretching.

[img width=600 height=421]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5098.jpg[/img]

Give yourselves some "growing room", a grain of powder, frozen condensation, or for some of you the thickness of a butterfly wing will prevent you from closing the bolt.

You DO NOT have a custom bench rest rifle with custom made reloading dies, you have a store bought Savage or Stevens rifle. I myself would be more worried about my expander button pulling my necks off center and making crooked ammo than worrying about an extra .002 head space.

A M14 at maximum head space has .010 head gap clearance or an air space of .010 between the rear of the case and the bolt face.

And for the people who cried about the end of the world because some people are using cartridge cases and tape to check head space, I will leave you with the following to think about.





Signed
Ed with his both eyes and all his fingers after 35 years of reloading.