Beginner Checking For Case Separation

This means the case can stretch as much as .011 . That is a HUGE amount of movement and why one of them cracked .
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Measure the headspace dimension on both the fired cases, and the unfired cartridges...
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Generally speaking; the "sweet spot" difference in expansion in regular (assuming max chamber dimension and minimum sized brass dimension) chambers should be about .005" to .006"--a field guage will probably let you "wander" up around .007" to .008" anything .01 or above you're potentially taking a walk in Kaboom land.
 
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bolt closes on the no-go gauge?

that still makes me think something might be flexing/binding causing more than acceptable over all chamber space while firing. i'm not sure what i think about it. it just smells fishy.
 
bolt closes on the no-go gauge?
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OK. When I chamber, I stop when the bolt just barely closes on the "Go"gauge
without force. I use the "No Go" to confirm,but its pretty much a "Code of the West" formality. I've built a lot of plastic injection molds and I know how to measure.
I do not advocate for sloppy chambering.

But folks seem to be a bit confused about the use of a "No Go" gauge.
1) Any force on the bolt handle implies some interference on the gauge.
By definition that means the chamber is right at max or actually slightly tight.
Its definitely not out of spec.
2) The "No Go " gauge applies to a new chambering. It ensures the chamber was cut to SAAMI spec. Remchester could legitimately make and ship 30% of its rifles that gauge the same way. The "NoGo" qualifies a new,unused chamber.

3) Rifles wear and headspace grows. Its the "Field" gauge that determines the chamber is unacceptable.

4) Nothing in the contract is about serving the handloader with long brass life. The default is a factory load goes "bang" one time when you need it.
The gun and ammo have done their job and owe you nothing.

Whatever hat tricks the handloader uses to extend case life boils down to "Whatever works"

Minimizing case stretch and excessive sizing are good plans.

There are multiple methods to achieve that result.

The Hornady case comparator is a good tool that will tell you "before" and "after" Its a tool that will let you control sizing and head clearance. Its OK fine!

In industry,making critical parts,we don't use calipers to qualify parts to print. We don't even use thread mics . We use plug gauges or thread gauges or ring gauges.Or gauge blocks and comparators.

I'm not saying you must do things my way. I prefer to use the bushing gauge as my standard. The step is useful as a go-no-go, but I measure over the bushing gauge with the brass inside. For myself,its more consistent than juggling and clamping to adapt the calipers. BUT! The Hornady system works! It fine!

On my bench I have a small slab of precision black granite. Its flat. It has a vertical mast I attach a dial indicator to.
If I stand the bushing gauge up on the granite, I can zero the indicator on the bushing or on the case head,depending on what I want to measure.

I can check sizing as fast as I can drop a case in the bushing and pass it under the indicator.

Do you need this setup? No. But I like it.

And,FWIW, if case neck protrudes beyond the bushing,its time to trim brass.

There is more than one way.

Some folks prefer an RCBS Precision Mic They work,too.

If you achieve controlling case stretch, no need to argue about the best tool.
 
If as it appears in post #6 ... 20-thou cast stretch ... we're looking at a chamber likely 10-thou over headspace max.

The Headspace comp will confirm that as shoulder movement -- and if so -- the barrel needs to be set back/rechambered.
 
The Headspace comp will confirm that as shoulder movement -- and if so -- the barrel needs to be set back/rechambered.
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The gunsmith did offer to set the headspace back for $250

Though, if the bolt didn't close on the field gauge the barrel doesn't NEED set back, right? I'm beginning to feel it may be worth it to not destroy brass as quickly and to give myself peace of mind(especially as a new reloader.)
 
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The gunsmith did offer to set the headspace back for $250
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That's not a bad price if it's "all inclusive" of whatever needs to be done--could end up needing lathe and truing work. before taking that dive I would have him examine the freebore, throat and bore and ask for an honest opinion about the condition--25-06 IS a barrel-burner when shot a lot and/or with hot loads. If the barrel is really otherwise close to or past "retirement age" you have the option of rebarreling or simply ditching the gun altogether. If you go the re-barrel route you then have the choice of going with a custom configuration--including a 25-06 AI equivalent and a faster twist to adequately stabilize the newer much higher BC modern .257 bullets. That's what I would do--but then again that's just my personal preference.:) I would not go with one of those pencil-thin barrels that some Vanguards have--they can whip around like wet spaghetti IMO.
 
If you go the re-barrel route you then have the choice of going with a custom configuration--including a 25-06 AI equivalent and a faster twist to adequately stabilize the newer much higher BC modern .257 bullets.
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I asked him about doing this! Not the AI part, but the faster twist. I think it would be neat. He quoted me 1k which was more than the cost of the entire gun and I've already spent way too much money recently.
 
The "Go" gauge is 2.0487 The "No Go" gauge is 2.0547 . It took light pressure on the bolt handle to close on the No Go. That indicates the headspace is right at 2.0547 but not more.The rifle did not accept the field gauge. That is all the field gauge told us.

From Go to No Go is .006 . I won't say its impossible to buy ammo shorter than 2.0487. Maybe.

But we cannot say the chamber can be blamed for more than .006 stretch.
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Anything beyond that would be short ammo.

2.0487 ammo would get .006 stretch assuming no springback.

What if we were loading Match Ammo for a Garand or M1A . Head clearance would be recommended at a minimum of .004 fitted to the individual rifle.Head Clearance of .006 is quite acceptable for aGarand or M1A.

I think we are making a mountain out of a molehill regarding the rifles chamber.
The difference between Minimum SAAMI ammo and a Minimum "Go" chamber I do not know.

If the ammo minimum size would give zero head clearance in a minimum "Go" chamber, then a .004 feeler gauge between the shellholder and sizing die should,in theory, get us.002 head clearance and very good case life.

More than one of those cases stretched 20-thou.
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Is that an assumption? Who measured it and by what method? Stretch is a function of before and after firing, so who qualified the ammo was proper length before firing?
It may well be the stretch of the brass was .020 or even more but it was not from a chamber with excess headspace.

Before we spend a bunch of the OP's money on a setback or new barrel, lets not jump to conclusions.

FWIW my friend the Wilson Bushing Gauge will quickly tell us the ammo length (in respect to headspace) is SAAMI length.
 
I very much appreciate your analysis, HiBC. Frankly, I kinda forgot about the wilsons bushing gauge and may get that as well.

I did attempt to measure the case of some unfired ammo from the same lot that I still have with my calipers, though its hard with the bullet still there.

I just re-measured. Varies from 2.483 - 2.487. It is hard is hard to be precise with off angle measuring with the bullet seated. Wondering if i scratched / messed the bullet up a bit, ah well.
 
khaines0625 said:
The gunsmith did offer to set the headspace back for $250



Though, if the bolt didn't close on the field gauge the barrel doesn't NEED set back, right? I'm beginning to feel it may be worth it to not destroy brass as quickly and to give myself peace of mind(especially as a new reloader.)
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The school I went to, they taught us the same, more or less.

Checking go gauge, any felt added resistance fails. If you bang on the handle to get the action close, it didn't close.

Checking no-go gauge, any felt added resistance is considered a pass. Failing no-go doesn't automatically requires service, unless there are associated issues; misfires, head separation etc. It is usually taken as a caution that it is getting close.

Failing field gauge, the rifle is to be removed from the "field". Very unusual the user hasn't been whining about problems already.

If the op plans to handload forever for the rifle, passing headspace check is just semantics, till he resells the gun. He can just size the brass to fit the chamber. I have done that a lot. No problem. No gauges, comparator, or wingdings are needed. Load light loads to form the brass to the chamber. Adjust down the sizing die in step of 1/32 of a turn (about 0.002”) till the brass chambers with little or no added resistance. Add 1/2 step and lock down the lock ring.

$250 for setting back barrel is fair price for rifle design that requires barrel vise, action wrench, and lathe work. Newer designs come with barrel nuts. For those they should charge less, or it can even be diy.

-TL

Sent from my SM-N960U using Tapatalk
 
To check the headspace length you need to measure from the case head,the base of the case,to a theoretical datum that is found by resting a circle of specific diameter on the shoulder.I don't know the diameter.Its near 3/8 in.
Your Hornady kit will provide the correct bushing.

The Wilson bushing gauge takes care of it for you.You just drop the case in and it rests on the datum. You can drop empty brass or loaded round in.
A step is ground at the top of the bushing giving you high and low limit.

For specific measurement, as in the change with sizing,you can just measure over the brass resting in the gauge.

Use a sharpie to write the number down inside your die box and you have a repeatable length to set up your sizing die. A set of feeler gauges is your friend.

Realize you are getting a fairly advanced handloading lesson,no charge!!
 
He can just size the brass to fit the chamber. I have done that a lot. No problem. No gauges, comparator, or wingdings are needed. Load light loads to form the brass to the chamber.
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When you say "light load" how light are we talking? keep in mind I have still yet to load a single round.

I bought some 87 gr speer bullets. My Lee manual says the starting load for H4831 87 gr jacketed bullet is 56 grains for H4831. Would this then be a "light" load or even lighter than that? How low can I go before being concerned?

Also, the powder I got is H4831SC. From what I've seen its just the short cut version of the H4831 and is interchangeable, yes?
 
Minimum book load usually will do for marginal cases like yours. If it still give you problems, there are a few different methods for fire forming. Google and you will find them. Even searching on this forum will yield you plenty.

Member Slamfire used to active here. I quite like his method. A bit unconventional or even controversial. But it makes a lot of sense to me. I still use it today.

-TL

Sent from my SM-N960U using Tapatalk
 
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H4831sc is the powder I use in my 257 Roberts Ackley Improved. I'm sure its an excellent powder for your 25-06. The SC works better through a powder measure.If you can score an 8 lb jug,I'd do it.
You can choose any bullet you want. I myself prefer heavier for caliber. I used 115gr Nosler Ballistic Tips at just over 3000 fps.

I think advertised ballistic coefficient is .435. Ballistic coefficient helps hold velocity and they do a little better in the wind.

You do things your way but I'd probably try to compare the 87 gr with the 115's
before I bought a lot of the 87's. The115's are great on deer and pronghorn and a prairie dog or coyote won't know the difference.
 
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More than one of those cases stretched 20-thou.
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Is that an assumption? Who measured it and by what method? Stretch is a function of before and after firing, so who qualified the ammo was proper length before firing?
It may well be the stretch of the brass was .020 or even more but it was not from a chamber with excess headspace.

Before we spend a bunch of the OP's money on a setback or new barrel, lets not jump to conclusions.
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See Post #6 and do the math. (21-thou before/after)
Granted, the 'before' was on loaded ammunition and so not a precise/fair test of actual case headspace -- but that's what the Hornady Comparator will reveal.

But I also don't think it's too much of a "stretch" (sic:D) to see separated cases on first firing/factory ammunition to be evidence of a sick puppy.

.
 
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well this is just a "for the record" i have bought cheep 223/556 that a few of them did split the case mouth on first firing.

that being said, i didn't like it! and i dont expect anyone else to like it if there weapon is busting cases, most especally on better domestic factory ammo, and the head blowing off of them.

so i hope everyone takes that to heart when telling the OP "it's ok" it might not be ok.
 
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