Please excuse the dumb question, but if I can get a fireformed, neck sized case to smoothly feed, and a no-go will not, what practical purpose does a go-gage serve?

I am also curious about the proper procedure for chambering an AI chamber. I thought that it was supposed to be reamed to fit a standard go, no-go gage and then turned in one turn. But considering that different manufacturers use different thread pitches that cant be right..

New to the chambering thing and need to know..

Not at all a dumb question......and the answer is that if you want all factory ammo to fit the chamber the go gage SHOULD be used. However it's fully acceptable to chamber your gun to fit your ammo.

When I make a chamber (example a .30-06) I get a fired case from someone and then buy the dies and full length resize the case fired in someone else's gun and then use that as a go gage and I add about .002 for clearance. In that way I always full length resize the cases and the dies are made for the gun.....or vice versa...Strangely enopugh I've never had trouble with factory ammo doing this but it's a very rare time I don't reload my own.

Sorry.....I can't comment on the AI chambers.....I just don't believe in them at all.

from a liaility stand point, HELL yes

jeffe

On the AI chamber...
The go guage for the parent cartrige becomes the no-go guage for the improved chamber. An Ackley go guage is then used to actually set up the chamber. It will be shorter than the parent-cartridge go guage.

You can't accurately set the headspace in the first place without a go gauge.

What chamber is the once fired necked size brass being fired in? If you're fire forming the brass in another gun, all your test is doing is showing that you have a sloppy chamber.

you can get by w/o a no-go, just use the go and a pc of shim stock, typically .006". is easier w/ the actual gage.

the chambers i cut myself i set headspace w/ a case full length resized in the dies i intend to use + .002" or so, then double check to make sure will close on a go after cinching down. i figure minimizes case stretch/ maximizes case life and also don't have to worry about setting the sizing die to just get the neck. has always worked fine except in one case of a 22-250 and then was only a problem w/ S&B ammo, which brand also gave problems in a 6.5x55. checking the 2 boxes in question, case lgt was all over the place from "under trim" to "over maximum"; this within a box of 20. "good" ammo has always worked fine this way.

granted, this is a sort of "one-off" approach: one set of dies to one chamber with a little leeway.

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Originally posted by vapodog:
and the answer is that if you want all factory ammo to fit the chamber the go gage SHOULD be used. .

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Good answer! Obviously a set of gages can get you closer, but apparently Im not the only one to ask this question as some of you have used other means. Since excessive headspace is far more potentially damaging then a tight fit I dont see the liability issue being a problem if a good No-go is used.

Jim, that makes perfect sense, thank you! Im guessing the "one turn in" everyone talks about is a generalization, possibly based on the original approach..??

if you get the chamber too tight and have bought the reamer (which i just resigned myself to doing every time) you can always go back and clean up a little. too deep and your into lathe work, realigning sights, all sorts of nastiness. so i usually try to chamber on the tight side. the 500ne i'm slowly bldg on a #1 i didn't even buy a gage; cut the chamber to just allow the breech block to close, then a little more. not rocket science but like i said, on that rifle esp, if turns out isn't enough is virtually no work at all to fix.

if you're trying to work off a no-go only on the other hand, all you'll ever know is that it isn't "too" deep. important for safety but you need to know the other direction for function.

If there is one thing you need to chamber a barrel correctly, it is a go gauge.
The problem with using a brass case is that it crushes a few thousandths.
A gauge, whether it is go or no-go does not crush, it is glass-hard steel and if the bolt is forced on it, it shatters.

They are, therefore, the most fool-proof system of measuring headspace and usually most accurate.
If you are a beginner, this is the way to go.

-Spencer

Most headspace gauges go and no go ar priced in the current Brownells catalog for under $30. Pretty cheap peace of mind if you ask me.

The one-turn-in is required if you have to re-index iron sights. The actual set-back required for an Ackley chamber will be in the .004-.006 range.

Some one set me straight! my understanding of any AI chamber, It should be set up to chamber a parent round? If it will fire a parent round, it has to be head spaced with the parent go/no go gauge. One pull of the trigger and you have fire formed cases. The one turn is to align the sights, if they are on the barrel.

My understanding is that the parent round should be a slight crush fit on the neck/shoulder junction.

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Originally posted by FVA:
My understanding is that the parent round should be a slight crush fit on the neck/shoulder junction.

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That is basically what Jim Dubell said. Many folks use the parent go gage - .004" to set the minimum for the AI chamber. This provides the slight crush fit you are referring to.

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Originally posted by bglenn:
Some one set me straight! my understanding of any AI chamber, It should be set up to chamber a parent round? If it will fire a parent round, it has to be head spaced with the parent go/no go gauge. One pull of the trigger and you have fire formed cases. The one turn is to align the sights, if they are on the barrel.

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For the purpose of being able to fire factory ammo in an AI chambering, the shoulder/neck junction of an AI is actually a tad shorter dimension than that of factory ammo due to the sharper angle of the improved shoulder. Hence you get the "crush fit".

Were they not made this way the headspace could easily be too excessive to fire factory ammo. Therefore a standard gage set doesnt apply.


Thanks again Jim..

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Originally posted by ShopCartRacing:
If you are a beginner, this is the way to go.

-Spencer

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Sound advice, thanks.

The reason go,and no-go gauges are presicion ground and made is the should be used,thats what they are for!! Don,t try anything else unless you are a qualified professional. vangunsmith

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Don,t try anything else unless you are a qualified professional.

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More sound advice.

If you are just checking headspace, an unfired case or live round with varying thicknesses of shim stock is OK to use if you know what you are doing.
I have chambered a few guns using this method, but I would not recommend it for someone who has not chambered before.
A .473 and Magnum set of gauges cover most calibers.
If you are doing a Magnum, a headspace gauge is almost invaluable because they headspace off the belt and it can be very easy to crush a brass case past the belt.

-Spencer

i would have to disagree abt the belted magnums at one level. at least long ago - and w/ modern mfg and tighter tolerances this may not be as big an issue - there was a tendency so i've read for belted magnum chambers to be somewhat sloppy excepting the headspace itself relative to the belt. per info from way back if a chamber were cut to headspace on the shoulder accuracy would improve as well as case life (less stretching). i just did my 300win mag that way, cut the chamber to match cases full length sized in my dies (plus .002" margin).

i'll concede a couple problems w/ this approach: 1) is one chamber - one case scenario and 2) likely complications w/ some factory ammo (which might matter) or other people's reloads (which will never matter).

current state of the art mfg precision this was probably unnecessary but the reamer is in a drawer and i can always fix it later if i have to.

no reason for a bolt action bottleneck ctg to even have a belt anyway.

Personally, I think the big reason for using a "GO" gauge is not for you, but for the next guy that gets that rifle. All this talk about using a brass case leaves me to think there are too many shorcuts out there being tried. The gauge is used to standardize things. GEEEEEZ!

a rifle i build for myself isn't built for the next guy. which is why in buying a custom gun - ANY custom gun and i don't care who did it - one should take the precaution of having things like headspace checked. and is also why any responsible gun dealer would have things like that checked before putting it on his rack.

i do things my way to suit me for my purposes today. and as long as it sits in my rack i'm not really under any obligation to do it in some way that someone else approves of. every thing i've said in this entire post relates to a person doing something HIMSELF for HIMSELF, nothing to do w/ a professional 'smith or custom builder making something for the market place. 2 different things. i fit my own barrels, cut my own chambers and do every bit of work remotely possible myself. when i'm done, it's "MY" gun in every respect. and i don't do these things for others so am not obligated to others.

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Originally posted by willmckee:
a rifle i build for myself isn't built for the next guy. which is why in buying a custom gun - ANY custom gun and i don't care who did it - one should take the precaution of having things like headspace checked. and is also why any responsible gun dealer would have things like that checked before putting it on his rack.

i do things my way to suit me for my purposes today. and as long as it sits in my rack i'm not really under any obligation to do it in some way that someone else approves of. every thing i've said in this entire post relates to a person doing something HIMSELF for HIMSELF, nothing to do w/ a professional 'smith or custom builder making something for the market place. 2 different things. i fit my own barrels, cut my own chambers and do every bit of work remotely possible myself. when i'm done, it's "MY" gun in every respect. and i don't do these things for others so am not obligated to others.

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Bingo...I agree.....except for one thing...

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and is also why any responsible gun dealer would have things like that checked before putting it on his rack.

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I'll bet we'd all be surprised as to the number of guns sitting on used shelves unchecked and further excess of headspace.

I like the idea of chambering my gun to the exact specs of my reloading die.

exactly. which is why i say like the x-files: "trust no one". until you check the chamber you've no idea what you got. and virtually all dealers i have no expectation they care abt anything but the sale price.

furthermore, i guarantee there have been many, many gunsmiths cutting chambers to cartridges rather than gages for a century at least, whether the customer knew it or not. and likewise many people having rifles built and specifying that minimum or special chambers be cut. and if one goes back into past practices they'll find i'm not the 1st person to advocate cutting belted magnum chambers to headspace on the shoulder. almost positive p.o. ackley for one; in his "handbook for shooters and reloader" as well as in his gunsmith columns. i'd not even pretend to second guess ackley.

the thing of trusting that a chamber is "good" because some alleged "qualified professional" cut it and checked it with a gage - suppose he cut the chamber to max. it's still "in". suppose the shooter has dies that were cut to min. he runs the die down against the shellholder (probably more common than not), bingo: excess headspace.

MY method - for ME! - i know exactly what i got and never have to think abt it again excepting worn out barrel or die change.

i haven't been an engineer for near 3 decades w/o learning a little along the way. and this ain't rocket science.

So then, you say you build these rifles for yourself. OK. SOunds as if you've done quite a few. OK. Now tell me something, when you say they are for you, aparently you keep all of these rifles. That's OK too. Now let's get really serious; if you no longer have a need for one of these, what happens to it. You would never think of selling one or giving one to a friend, or worse, your not so good friend. Or worse yet, do you plan on dying in the future and what will your widow do with these "items"? Bottom line; you owe it to everyone to do it right.