I had a discussion with a gunsmith a while ago regarding barrel headspace. I had a 98 with a new barrel chambered in 7x57. It was headspaced to a go-gauge + 0.004”, and double checked. However the bolt wouldn’t close on new unsized Norma brass. FLSed was fine, although the die needed screwing in quite a way. The gunsmith said this meant the headspace was too tight. I said it closed on a go gauge, and a go-gauge with 0.003” shim but not 0.004”, he said that didn’t matter. Surely a go-gauge trumps new brass?

quote:

Originally posted by brnomauser:
I had a discussion with a gunsmith a while ago regarding barrel headspace. I had a 98 with a new barrel chambered in 7x57. It was headspaced to a go-gauge + 0.004”, and double checked. However the bolt wouldn’t close on new unsized Norma brass. FLSed was fine, although the die needed screwing in quite a way. The gunsmith said this meant the headspace was too tight. I said it closed on a go gauge, and a go-gauge with 0.003” shim but not 0.004”, he said that didn’t matter. Surely a go-gauge trumps new brass?

Are you absolutely sure the proper headspace gages were used? Gauge trumps new, unfired brass every time. We make the brass conform to the chamber, not the chamber to the brass.

Funny this.

I have not used a headspace gage for our rifles for years.

I use a brand new fired case.

Once the bolt closes on it, that is it.

Never had anyone complain.

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Originally posted by slivers:

quote:

Originally posted by brnomauser:
I had a discussion with a gunsmith a while ago regarding barrel headspace. I had a 98 with a new barrel chambered in 7x57. It was headspaced to a go-gauge + 0.004”, and double checked. However the bolt wouldn’t close on new unsized Norma brass. FLSed was fine, although the die needed screwing in quite a way. The gunsmith said this meant the headspace was too tight. I said it closed on a go gauge, and a go-gauge with 0.003” shim but not 0.004”, he said that didn’t matter. Surely a go-gauge trumps new brass?

Are you absolutely sure the proper headspace gages were used? Gauge trumps new, unfired brass every time. We make the brass conform to the chamber, not the chamber to the brass.

Absolutely correct!

I never chamber to brass unless specifically requested to do so.
Brass is all over the place dimensionally even from the same manufacturers batches.
How can you even be sure the resizing dies will work after you resize fired brass from one off these brass set chambers!
Gauges all the way.
BB

quote:

Originally posted by bigbull:
I never chamber to brass unless specifically requested to do so.
Brass is all over the place dimensionally even from the same manufacturers batches.
How can you even be sure the resizing dies will work after you resize fired brass from one off these brass set chambers!
Gauges all the way.
BB

I can't think of any situation where I'd chamber longer than the gauge; I will go shorter to make the chamber tighter. Particularly with magnums. I routinely chamber magnums till they will not quite close on the go gauge; that avoids about .010 of brass stretch on first firing of the brass, as the belts on most all brass allows for way too much clearance. After the first firing, of course the cartridge is reloaded to headspace on the shoulder, just like any cartridge, as if the belt wasn't there.

Chambering to greater headspace to match a batch of brass that was not manufactured to correct dimensions would be a recipe to have a case failure on a properly manufactured cartridge, particularly a piece of factory loaded ammo.

With the very generous tolerances allowed by SAAMI, and the fact that no one is mandated to follow their specs anyway (this isn't Europe), it is a miracle that anything fits. I use gauges, but when I know a guy who likes to full length size everything to absolute min, I cut the chamber to match. Never longer though; make them size them first.

Sizing the brass before using for head spacing is not accurate unless the brass is long, in my experience the brass is always on the short size and needs to be fireformed before sizing. I have never found a case that the unfired un-sized brass is of any value, it is simply made small enough to be used in any gun on the planet without fault and it does that very well.
BB

quote:

Originally posted by slivers:
Are you absolutely sure the proper headspace gages were used? Gauge trumps new, unfired brass every time. We make the brass conform to the chamber, not the chamber to the brass.

the gauges were supplied by the barrel maker as a set of go/no go gauges. They’re clearly used, and the only discernible marks are “7mm/0.284”. One is about 0.010” longer than the other. Being Norma brass I would have thought it shouldn’t be too far out.

But I wonder if what I’m using as a go gauge is actually under spec for some reason. I wonder if it was chambered so new unsized Norma fits and double checked with a no go gauge it wouldn’t be a bad place to start? There is another barrel to do so I’ll get a second chance.

quote:

Originally posted by ssdave:
I can't think of any situation where I'd chamber longer than the gauge; I will go shorter to make the chamber tighter. Particularly with magnums. I routinely chamber magnums till they will not quite close on the go gauge; that avoids about .010 of brass stretch on first firing of the brass, as the belts on most all brass allows for way too much clearance. After the first firing, of course the cartridge is reloaded to headspace on the shoulder, just like any cartridge, as if the belt wasn't there.

Chambering to greater headspace to match a batch of brass that was not manufactured to correct dimensions would be a recipe to have a case failure on a properly manufactured cartridge, particularly a piece of factory loaded ammo.

my understanding of SAAMI (or CIP) headspace is that it fits in a certain range - ie there is a min and max. The bolt must close on a go gauge, and it must not close on a no-go gauge, this puts the chamber in the correct range. Is this incorrect? Assuming it is, and you don’t want a super tight target rifle, but more a reliable hunting rifle surely something that sits a bit more in the middle of the range is desirable? How do you do that when headspacing a long chambered barrel? It seems to me using a go gauge with a shim is a good way to measure the headspace. And so long as a go chambers and no go doesn’t it’s still correct?

I’d you’ve gone shorter than a go gauge doesn’t that mean you’ve gone outside of spec and there’s a chance some factory ammo won’t chamber?

I've seen this type of discussion kicked around for a long long time..Just use the gages. That's why they're called gages.

You want to make the chamber longer or shorter..don't stamp or engrave the caliber. Write a narrative on the barrel so some future owner will know what's what

Gauges, however, vary with the maker. No one has a gold set of gauges.

I think that there is a reason that it is recommended that NEW brass be sized before using! In fact I think it would be advisable to neck up the brass first then neck down for a crush fit to fit exactly to your chamber.
The important thing is not the specs of your chamber but the fact that the brass fits it as best as possible!

Just my musings!

Hip

Waiting for the bashings!

Hip

Hip, it all depends on what you're trying to accomplish. For your own rifles, best fit and best function, you can tailor the loads to the rifle. What you're proposing is creating a situation similar to once fired brass, that can then be tailored to your chamber.

Non-belted cartridges, I chamber in the gage range, at the level requested by the customer, whether that is close to minimum headspace for someone who will be doing carefully tailored loading or close to max to insure any ammo, regardless of source or brand will go in and work.

For 95% of the shooting public, that wants factory ammo to just work, the answer is to chamber to gage, and just expect them to shoot factory ammo. I aim for the mid range for those.

I actually don't chamber to gage, I chamber to measurements, as do most barrel fitters. The gage is used to CHECK you're work, as a secondary safety check.

I first started doing magnums short when I was selling pre-threaded/short chambered barrels. If I chambered a magnum .005" to .007" shorter than min, and sent it to a client, they always reported back that they could just use it as is and no problems. I then tried it, went through every piece of ammo I had and found that magnum brass is pretty universally manufactured with grossly large headspace on the belt. The usual is .008 to .010" shorter than the go gauge. After firing, if you minimally neck size so it headspaces correctly on the shoulder, the belt is totally superfluous.

I size ALL my brass no matter if it is rimless, belted or rimmed to headspace on the shoulder. The exception(s) of course straight/tapered cases.
Naturally if you are doing the work you would want ALL cases to chamber without any problems.
Years ago some brands of cases where terrible (there weren't that many brands readable available then). I don't know how many decaping pins that I broke due to badly off centered flash holes.

Hip

I would have just tried one or two factory rounds and if they fitted without any undue bolt interference then would just assume the Norma cases need FL resizing before loading. I wouldn't trust any new cases made nowadays no matter who manufactured it, quality control has gone out the window for many manufacturers.

Thanks guys. I’ve had a better look at the gauges they sent me second time round, and have measured the protrusion against brass and things are now adding up. New unsized Norma brass is 0.002” under the go gauge. I still think it would be better headspace it somewhere between go and no go. So it’s still in spec but pretty much guaranteed to chamber any ammo anywhere (rather than a tight chamber possibly rejecting some ammo), and I’ll just size my brass to suit. Am I missing something, is there a reason not to do this with a hunting rifle?

It sounds, to me, as if everything is exactly as it should be.
A headspace gauge is reasonably precise in length to the datum line and the shoulder angle is also precise. If the shoulder angle on the reamer is exactly the same as on the gauge, measurements taken with the gauge will be valid, related to the chamber produced by the reamer. If the shoulder angle on the reamer is a little off, the shoulder of the gauge may contact somewhere other than on the datum and any measurements are invalid.
The same is true of the brass; if the shoulder angle varies, contact will be elsewhere other than the datum. Regards, Bill

Well spoken!

quote:

Originally posted by Bill Leeper:
It sounds, to me, as if everything is exactly as it should be.
A headspace gauge is reasonably precise in length to the datum line and the shoulder angle is also precise. If the shoulder angle on the reamer is exactly the same as on the gauge, measurements taken with the gauge will be valid, related to the chamber produced by the reamer. If the shoulder angle on the reamer is a little off, the shoulder of the gauge may contact somewhere other than on the datum and any measurements are invalid.
The same is true of the brass; if the shoulder angle varies, contact will be elsewhere other than the datum. Regards, Bill

good point Bill, I hadn’t considered the reamer may not quite match the gauge - that would explain inconsistencies!

quote:

Originally posted by Bill Leeper:
It sounds, to me, as if everything is exactly as it should be.
A headspace gauge is reasonably precise in length to the datum line and the shoulder angle is also precise. If the shoulder angle on the reamer is exactly the same as on the gauge, measurements taken with the gauge will be valid, related to the chamber produced by the reamer. If the shoulder angle on the reamer is a little off, the shoulder of the gauge may contact somewhere other than on the datum and any measurements are invalid.
The same is true of the brass; if the shoulder angle varies, contact will be elsewhere other than the datum. Regards, Bill

You are describing a faulty gauge or reamer.
In this case the gauge is at fault from all indications but maybe not. I have never experienced the discrepancies between the reamer and gauge that theyy caused a problem and even i I did I would have no way of validating the angles without some pretty expensive equipment.

As long as you are using the proper gauge, I'd just run that new brass through my FL sizing die, make sure it was of proper length, and call it good. "GO" + .003" is quit acceptable for a hunting rifle.

Over the last few years I have had more issues with new brass being difficult to chamber than I ever had in over 50 yrs of reloading. Winchester has been the make with the most issues. I had a bag of 280 headstamped cases that were actually 30-06 brass. I sized them and used them. Many others that will not go into a seating die or a rifle chamber. I think quality control have all retired and they never replaced them

The fact that the brass chambers fine after a FL size is very telling.

quote:

Originally posted by bigbull:

quote:

Originally posted by Bill Leeper:
It sounds, to me, as if everything is exactly as it should be.
A headspace gauge is reasonably precise in length to the datum line and the shoulder angle is also precise. If the shoulder angle on the reamer is exactly the same as on the gauge, measurements taken with the gauge will be valid, related to the chamber produced by the reamer. If the shoulder angle on the reamer is a little off, the shoulder of the gauge may contact somewhere other than on the datum and any measurements are invalid.
The same is true of the brass; if the shoulder angle varies, contact will be elsewhere other than the datum. Regards, Bill

You are describing a faulty gauge or reamer.
In this case the gauge is at fault from all indications but maybe not. I have never experienced the discrepancies between the reamer and gauge that theyy caused a problem and even i I did I would have no way of validating the angles without some pretty expensive equipment.

It doesn't matter about gages or chamber reamers, just try some factory ammo in the rifle. If it fits the chamber is fine and like myself and others have said with the crap brass on the market today, that is the first thing to suspect. As I posted earlier I would have been trying factory ammo first before worrying over gages and chambers.

One thing I’ve found is when full length sizing, ie shell holder contacting die, you can end up with .010” or more headspace on a spec chamber.
Nowhere in the die instructions does it mention sizing to suit chamber.

These days it's easier to get reamers than brass. I've taken to buying brass in batches, measuring it, and having reamers made.

I hand load everything except rimfire though...

2¢

quote:

Originally posted by jpl:
These days it's easier to get reamers than brass. I've taken to buying brass in batches, measuring it, and having reamers made.

I hand load everything except rimfire though...

2¢

Funny but sad situation we are living.

quote:

Originally posted by bigbull:

quote:

Originally posted by Bill Leeper:
It sounds, to me, as if everything is exactly as it should be.
A headspace gauge is reasonably precise in length to the datum line and the shoulder angle is also precise. If the shoulder angle on the reamer is exactly the same as on the gauge, measurements taken with the gauge will be valid, related to the chamber produced by the reamer. If the shoulder angle on the reamer is a little off, the shoulder of the gauge may contact somewhere other than on the datum and any measurements are invalid.
The same is true of the brass; if the shoulder angle varies, contact will be elsewhere other than the datum. Regards, Bill

You are describing a faulty gauge or reamer.
In this case the gauge is at fault from all indications but maybe not. I have never experienced the discrepancies between the reamer and gauge that theyy caused a problem and even i I did I would have no way of validating the angles without some pretty expensive equipment.

No, I am describing a gauge and reamer made within industry tolerances. Shoulder angles will vary; though not by much. They will almost certainly vary on the brass. If the brass is contacting at the juncture of neck and shoulder, the angle on the brass may be too shallow. If the brass is contacting at the juncture of shoulder and body, the shoulder on the brass is too sharp; relative to the chamber. Both situations can exist although the chamber is perfect vis a vis the datum line. Regards, Bill

Sounds like the gauge is worn undersize.

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Originally posted by custombolt:
Sounds like the gauge is worn undersize.

?????? I have been using hardened steel gages of all types over my 48yrs of machining and can say it is a rarity to have one wear out. Headspace gages don't get nearly the use that precision gages in a production machine shop do, and those can take hundreds of thousands of cycles before they are out of calibration.

Well something isn't right. What else could it be. Brass?

quote:

Originally posted by brnomauser:
Thanks guys. I’ve had a better look at the gauges they sent me second time round, and have measured the protrusion against brass and things are now adding up. New unsized Norma brass is 0.002” under the go gauge. I still think it would be better headspace it somewhere between go and no go. So it’s still in spec but pretty much guaranteed to chamber any ammo anywhere (rather than a tight chamber possibly rejecting some ammo), and I’ll just size my brass to suit. Am I missing something, is there a reason not to do this with a hunting rifle?

You've got it exactly right. Chamber to the gauges, and size your brass to fit. Don't chamber longer to avoid sizing new brass, that isn't necessarily perfectly sized.

quote:

Originally posted by custombolt:
Well something isn't right. What else could it be. Brass?

He got ahold of a bad batch of brass. We have gotten used to being able to load new brass straight out of the package, but just like the instruction manual that comes with a new firearm, it gets thrown away with the packaging. Most new brass comes with the instruction to run it through a sizing die before loading, if for no other reason than to remove dents in the necks. It should be just common sense (which isn't so 'common' anymore) to check the over all length and de-burr , also, bullets will seat into the neck easier. And then there is 'prepped' brass that Nosler (I think!) is offering. One more thing,, if you doubt your gage(s), get another, they are not terribly expensive!

Thanks for both posts slivers. Since your experience is far and above mine, suffice it to say I have been educated again.

brnomauser

Got a mate with a 7X57 to check the gauges in his chamber just to rule them out? Sorry guys. Seems odd that a barrel maker would include a used set of gauges with a new barrel.
P.S. RWS brass is perfect.

Thanks for the in depth discussion guys, I’m confident it’s all good now. Gauges, brass and dies agree. My issue was more that an experienced and respected gunsmith was adamant new unsized brass held more sway than gauges. Being an amateur I felt I couldn’t argue the point

quote:

Originally posted by custombolt:
brnomauser

Got a mate with a 7X57 to check the gauges in his chamber just to rule them out? Sorry guys. Seems odd that a barrel maker would include a used set of gauges with a new barrel.
P.S. RWS brass is perfect.

unfortunately I’m in a pretty sparsely populated rural area, although there are quite a few shooters 223, 22-250, 243 and 308 are what is used. If a local knows what a 7x57 is I’m lucky - the nearest person I know with one is about 1200k away

I get the same puzzled look here when I mention 7X57.

Lesson learned. Never had any bad Norma cases. But just a couple hundred cases is not a very good example. But thinking back a few years, someone else on here mentioned that Norma (correct me if I'm mistaken) would occassionally farm out some of their brass orders and mistakes "could" be made. Sorry I forgot about the post.
Happy shooting Sir.
CB