Sounds to me you had good advise. I once had a 303Brit, which I know are prone to cases stretching, but that rifle would initially stretch brass but after that they were OK. I don't shoot huge strings of ammo, so once these cases settled down to the slightly larger chamber I got normal amount of wear from them. Just using factory might be his desire to sell you plenty. OK the brass stretches but even then you should get a fair few reloadings before they become defunct. Compare the cost.

 

Set the dies so as to get .002" of airspace between the bolt face and the head. I do that by placing a feeler gauge between the shell-holder and the die mouth. Run the ram up, place feeler gauge across shell-holder, tighten down the die tight-tight by hand and tighten the locknut. Having a dummy chamber makes this very easy. You'd have to do it by hand by sizing cases with different feeler gauges until you get a very slight crush fit, then use the previous feeler gauge to back off the die by that .002 inches.

 

Its a Savage, so if you have excessive headspace anybody with a gauge and a few tools can correct it in just a few minutes.

 

If all you're ever going to shoot is factory loaded ammo, that's fine. But, if you want to reload and get the best performance, then he's wrong.

You have a headspace issue because the shoulder is being set back too far on sizing. That can cause the head separation you're seeing on cases with a couple cycles on them, and even on first firing in extreme cases. If you don't have one, get a Hornady Headspace gauge set. That will allow you to accurately measure cases fired in that rifle and then set the sizer for shoulder set back of .002". Start with new brass and fire a moderate load to fireform the case, then measure it (take an average from several cases), adjust the sizer, and you're good to go.

There's no reason those cases shouldn't be good for 10-15 reloads (with a couple of anneals in there).

 

Rifter has nailed it.

With the headspace issue, and if you sized according to die manufacturer's directions (contact shellholder + ¼ turn), you have followed the recipe for case separation exactly.

 

Rifter has the right idea if you just want to leave the rifle alone but IMO, BSN has the way to go. It's too easy to set back a Savage barrel. You don't even do any machine work!

Headspace on a 270, like most cartridges, has a .010 tolerance so the safe path forward would be to see if your father's rifle passes a field gage. I'm guessing it will not.

As another poster stated in reference to his 303 Brit, there's ways around the issue but I, personally, only employ those techniques on rifles I own and know intimately.

 

I would correct the head space on the Savage before I went to the trouble of making special brass for just one rifle, setting the head space on a Savage is gravy.

 

You can set that barrel back, but then you have to recut the chamber. If its going to clean up right, that means setting it back at least one whole thread. That takes a skilled gunsmith, and it ain't cheap. Depending on what the barrel profile is, you may have to do some stock work as well.

In addition, even if the headspace is perfect when checked with G0/NO-GO/Field gauges, you can still get head separation. If the sizing is set up like I recommended, it doesn't matter whether its perfect or if the chamber is a few thou too long. You are setting the headspace based on the measurements obtained from cases fired in that rifle. Doing it that way, it will always be correct for that rifle. And that's the correct way to do it.

 

Hows about just getting a neck-sizing die? The case will retain the chamber dimensions and all that need be done is to squeeze down the neck. No need to lube; saves time. Can't be too hard to get such a die or set of dies. Can't be all that expensive for a standardized round, either. I had to have mine made. Took a long time and cost close to $200 for two sets...

 

Why does everybody try so hard to do it the hard way when all you need is a $35 Hornady Headspace gauge? If you use that to set your sizer, you don't need to set the barrel back, you don't need to buy a neck sizing die (you'll still have to full length size those cases at some point, so what have you accomplished, especially when it will cost as much as the gauge set?).

Also, on that Savage that can be adjusted, if its only a couple thousandths off, why mess with the rifle when you can use the gauge to set the sizer correctly? That's the correct way to set up the sizer whether the chamber is short, long, or right where it should be.

 

CAUTION: This post discusses loads or load data that is not published for the cartridge(s) mentioned. Neither the writer, The Shooter's Forum, nor the staff of The Shooter's Forum assume any liability for damage or injury resulting from using this information. DO NOT ATTEMPT TO DUPLICATE THE DESCRIBED LOADS without first working them up from a published safe starting level charge while watching for pressure signs. If you don't know how to do that, don't try.


Jake,

It sounds to me like someone had that barrel off and put it back incorrectly. I've had a tour of the Savage plant, and the way the ladies who were setting headspace at the time were doing it, there's no way one could get through with 20 thousandths of extra space.

If you sent the rifle to Savage, they would probably fix it without charge, but there will be shipping. Also, for liability reasons, they will likely put the trigger back into factory original condition and pull weight, which you probably won't like.

It is not difficult to adjust a Savage barrel for yourself. Assuming you have a bench vice, you can actually do it with just a barrel nut wrench and small hardwood board that fits through the ejection port and magazine well opening to give you a pry bar that won't mar the finish. The $25 Wheeler barrel nut wrench at Midway should do one gun OK. It's metal is soft, though, so if you intend to do this more that once, I suggest spending $41 to get a better made wrench from Sharp Shooter Supply. As compared to returning the gun to the factory, we are still talking shipping cost levels of expense.

You can use a factory new case or a commercially loaded round of ammunition as an improvised headspace gauge, as long as you have a gentle touch, have stripped the bolt so you can feel delicately when the chamber and case shoulders meet while screwing the receiver onto the barrel. After just kissing a new factory round's shoulder, tightening the barrel nut will generally draw (stretch) the chamber about 0.003"-0.005". Since the new cases are most often about -0.002 from chamber minimum, that amount of draw lands you inside the GO and NO-GO gauge length difference, right where a factory new chamber normally is.

You can test for the right headspace by putting shims between the bolt face and the head of the factory new case or round until you just feel it kiss the shoulder again. Figure a piece of typing paper is usually 0.003" to 0.004" thick and will make a good test shim. If you find you got it wrong, loosen the nut and figure to turn the receiver in or out about a sixteenth of a turn (¼ of 90°) for about 0.003" of reduction or increase in headspace, as needed, or turn it less than that, as needed.

There are several YouTube videos demonstrating setting the savage headspace. This one uses a plier handle the way I would recommend using a hardwood plank (e.g., a spare length of tongue-and groove floorboard) to avoid the marring mentioned in the video. This one shows a simpler vice setup. Unlike guns where the barrel screws into the receiver directly, the Savage barrel does not require the barrel to be held firmly enough by the vice to withstand the tightening torque, so you don't need a proper gunsmith's barrel vice for it. Both videos show a GO and NO-GO gauges being used. But as I suggested, you can get away with using a new case or cartridge if you are careful and gentle and strip the bolt. You cannot jam the case tight with the bolt as some do with headspace gauges (not the best practice, anyway) because that will resize a brass case shorter.

—

As you've also found, that extra headspace does not stop functioning. Firing a new case, it is just pushed forward in a loose chamber by the firing pin until the extractor hook stops it going any further (i.e., headspacing on the extractor hook rather than the case shoulder). That defines the maximum head stretch you can get. After that, the shoulder blows forward into any additional headspace there may be, same as fireforming a wildcat or an Ackley improved cartridge from a parent cartridge does.

If you are starting with new brass and don't want to suffer even an extractor hook's depth of pressure ring stretch, you can avoid it by fireforming the case at reduced pressure to get most of the shoulder blown forward before loading normal pressure loads. I've done this with Trail Boss loads of about 85% loading density and using a heavy-for-the-chambering bullet. I shooting these with the ejector removed, (the case freshly annealed if it was previously fired) and the bullet jammed 0.01" into the lands to help resist the firing pin shoving the cartridge forward. YMMV. There are other fireforming methods that involve pistol powders and cream of wheat-filler, oiled cases and low starting loads, etc.

Once you have the fireformed cases, just leave your sizing die high in the press so it sets the fireformed shoulder back only a couple of thousandths. That will still produce good, smooth feed from a magazine. You could also try neck sizing-only, as mentioned in an earlier post. You just can't count on smooth magazine feed with neck sizing. It depends on the load pressure as to how many firings cause neck sized cases to become too tight to feed and to require full length resizing per the above method anyway.

These reloading methods marry the brass to the gun, as if it were a wildcat chambering, but they work just fine.

 

So I loaded up some brand new Remington brass without sizing it in any way. I measured 8 cases and they all measured 3.231". I loaded up RL22 for these loads and the 130 grain Speer Boattails I've been working with. The round fired ok, but when I returned home I measured them and this brass, too, stretched significantly. Most measured right at 3.250", so again the stretch was about .02".

Was I advised correctly?

Thanks,
Jake

Advise correctly? I do not know what advise was given. The information you have given when referring to stretch seems to have driven most members into the curb. Reloaders do not make a distinction between stretch and flow, I always ask "it is stretch? Or is it flow? Or is it both?"

I am only concerned with stretch between the case head and case shoulder/datum. 3.231" is not relative, I would be looking for a number like 2.052" -minus .007". You make a reference to .020", if you are referring to an increase in case length from the shoulder/datum (.375") to the case head of .020" then I would say the rifle has a problem. I have one that has an additional .011" in length from the shoulder to the bolt face, for me? Not a problem. I form 30/06 cases from 280 Remington cases, the additional length of the 280 Remington case of .051" allow me to form the shoulder anywhere I want it when offsetting a long chamber. I only have one head space, my chamber has head space, my case does not have head space. I off set the length of the chamber with the length of the case, and if I had a problem with a Savage with barrel nut I would adjust the chamber head space.

F. Guffey

http://www.saami.org/PubResources/CC_Drawings/Rifle/270 Winchester.pdf

and then? many times the case gets longer from the shoulder back to the case head and 'believe it or not', the case did not stretch.

 

Deleted to keep the peace.

 

No disrespect to anyone else, but Uncle Nick just gave you everything you'd need to solve this problem three different ways. Read and reread his post until it makes sense. I would second his advice on adjusting the headspace yourself.

 

+1 to what Broom said. Then, once the headspace is adjusted correctly, set the sizer for proper setback like I said. The Pearly Gates will open and all will be right with the world!

 

+1 to what Broom said. Then, once the headspace is adjusted correctly, set the sizer for proper setback like I said. The Pearly Gates will open and all will be right with the world!

All I had was 3-4x fired brass from my Model 70 and a Remington 700, so I chose about 25 good-looking cases and FL sized them. I loaded up 3-4 different loads, all at least 1-3 grains below max, so NOT hot loads. I started shooting them at the range, and I noticed that every single case was separating at the head. Some broke completely in two, and others just cracked or showed the thinning line. After a few rounds I just stopped. The only thing i could figure at the time was that the brass was older than I thought or I had set the shoulders back too far and the Savage was stretching the brass because of excessive headspace. When I got home I measured the fired, mostly-separating brass and it had stretched up to .025" from trim length.

While most everyone is giving 'atta-boys' and high fives to their friends allow me to include jakesnake66. Include as in participate.

Jakesnake66, in the quote above you said you choose cases fired in another rifle. You said you full length sized the cases. QUESTION? Why? For years I have purchased fired cases from a firing range for the sole purpose of finding cases that have been fired in long chamber from the shoulder to the bolt face. Cases that are longer than minimum length are not available for a reloader that knows what they are doing. A knowledgeable reloader must become a case former as in form cases that are too long from the shoulder to the case head to chamber.

For the 270 Winchester chambdeer I use 280 Remington cases, it is a fool proof method/technique. The 280 Remington case is longer from the shoulder to the case head than the 270 Winchester case by .051" When forming 280 Remington to 270 Winchester I adjust the forming die/sizing die off the shell holder .010", After completing the forming process the case should not allow the bolt to close, but if the bolt does close start forming another case with a larger gap, I would suggest .015", if the bolt closes on the longer case keep trying. A case former that knows what they are doing can form a case that will not allow the bolt to close to determine the length of the chamber in thousandths. convincing someone it can be done is something I do not have enough time to do. It has been done for at least 65 years.

Forming for the purpose of determining the length of a chamber does not mean the case former/reloader has to form the case to fire, forming aids the reloader/shooter/collector to determine the length of the chamber.

F. Guffey

 

Once again, you have made a post that is probably full of some useful information, but your writing style makes it a real chore for me to try and figure out just EXACTLY what it is you're saying! I do not believe you are being purposefully obtuse or obfuscating, because I sincerely believe you know what you're doing AND what you're saying. It's just that, I can't make heads nor tails of it.

Can't a guy just take a case fired from his rifle and gradually adjust a resizing die (neck-sizing or F/L) to the point that a sized case just barely fits into the chamber again? I mean, the process really IS that simple...so what's with all the other ramblings?

 

Head space: good advise, bad advise and no advise

A reloader west of Huntsville, Alabama was seeking help, he had 18 plus Mausers, he wanted to check the length of the chambers. Gunsmiths in the area said "It can't be done" He had both chambers, the .323 and the .318. His quest for a better answer lead him to a reloading forum, same answer. Well not quite, I said "No problem".

As everyone would expect no one ask "HOW!" to shorten the story I made him 20 gages, from the shoulder to the head of the case, I made gages that started at minimum length then went up to .024" longer than a minimum length case.

He was surprised at the number of rifles that had go-gage length chambers, he was also surprised two of the rifles had had chambers that were .012" longer than a field reject length chamber.

And the forum? they still do not believe it can be done. I could have made one gage, again, I will not live long enough to change closed minds.

F. Guffey

 

A reloader west of Huntsville, Alabama was seeking help, he had 18 plus Mausers, he wanted to check the length of the chambers. Gunsmiths in the area said "It can't be done" He had both chambers, the .323 and the .318. His quest for a better answer lead him to a reloading forum, same answer. Well not quite, I said "No problem".

As everyone would expect no one ask "HOW!" to shorten the story I made him 20 gages, from the shoulder to the head of the case, I made gages that started at minimum length then went up to .024" longer than a minimum length case.

He was surprised at the number of rifles that had go-gage length chambers, he was also surprised two of the rifles had had chambers that were .012" longer than a field reject length chamber.

And the forum? they still do not believe it can be done. I could have made one gage, again, I will not live long enough to change closed minds.

F. Guffey

I agree that Uncle Nick has probably identified alteration of the barrel position as the reason for this problem, and given all that is needed to set it right, in what is, after all, a modern rifle. If it was an older one, I would have suggested careful comparison of the cases fired from this rifle and one known to give long brass life, to see if the diameters are different. A caliper is better than a micrometer for this, as you can set two cases side by side in the jaws.

I believe those separating rounds wouldn't have done the same with one more firing in the good rifle, but it wouldn't have hurt to divert some of the batch to see what happened in that rifle instead.

We sometimes see the use of a case as a headspace gauge denounced as the great sin against God and Man. Well, maybe. In the unlikely event that you are doing something which is increasing the headspace, which is not a little dangerous but very, you aren't going to detect it that way. But if you size a case in a reputable maker's die of modern manufacture, till the shellholder touches or very nearly touches the die, you aren't going to take any harm by adjusting the barrel two or three thou over chambering that.

All kinds of people made Mausers, under all sorts of conditions It is pretty routine to find that much of an excess headspace, but the Mauser extractor is extremely good at holding the head close against the bolt face. Other rifles (like, I suspect, this Savage) allow or even force the case home for most or all of the way the headspace permits. It makes the difference between the safely-stretchable head or the dangerously-stretchable area just forward of the solid web doing the stretching.

You might even see a little mushrooming of the primer edge into the groove that is normally left between primer and surrounding case-head. Greatly excessive pressure will do that, but with moderate loads, as used here, it indicates that first the primer has been extruded and then the case has moved backwards to meet it, all while the pressure is still high.

 

I believe those separating rounds wouldn't have done the same with one more firing in the good rifle, but it wouldn't have hurt to divert some of the batch to see what happened in that rifle instead.

I have absolutely no interest in what those rounds would have done in the other rifle. When it comes to sizing and forming the only case available for the long chamber is 'cylinder brass', a 30/06 type straight wall case with a 35 Whelen head stamp from R-P. the case from the mouth of the case to the head of the case is 2.650" long. A prefect case for wildcatters.

After cylinder brass there is minimum/full length and nothing. Except! for me. I have 30/06 cases for 8mm57, 7.7 Japanese etc. For the 30/06 chamber, 338/06 and 35 Whelen 30 Gibbs I have 280 Remington cases. When I determine the length of the chamber I form cases to fit.

Jakesnake66 choose to use cases fired in another rifle, Jakesnake66 should have know the length of the chamber in the other rifle. He choose to full length sized the cases. I have one 30/06 chamber that is .002" longer than a field reject length chamber. Should I choose to size cases for a chamber of unknown length I could use the long cases, I would not full length size the cases to minimum length, I would adjust the die off the shell holder .010", then size a case, if that case chambered I would adjust the die off the shell holder .015".

Respect for Unckelnick? I believe he is one of the very few that is capable of keeping up.

F. Guffey

http://www.z-hat.com/Cylinder.htm

 

I have absolutely no interest in what those rounds would have done in the other rifle.

After cylinder brass there is minimum/full length and nothing. Except! for me.

Respect for Unckelnick? I believe he is one of the very few that is capable of keeping up.

My, my. You certainly are a legend in your own mind

 

Have just finished having the opposite problem fixed in an older .308 110FP. The rifle was hard to close on a FL sized case and a neck sized case was more of a problem. Took the rifle to local gunsmith who discovered that the bolt would not close on a "go" gauge. Basically opened the chamber up without moving the barrel. From all appearances, the rifle had not been messed with. Otherwise it worked well. Better now that it has been fixed.

 

The rifle was hard to close on a FL sized case and a neck sized case was more of a problem.

William A. Reed, Short chambers, I have chambered rifles with short chambers for reasons unknown to reloaders. I am a case former, I form cases for long and short chambers. I do not grind the bottom of the die, I do not grind the top opf the shell holder, I use the feeler gage to raise the case head off of the deck of the shell holder. When forming cases for short chambers I form cases that are shorter than a full length sized case by .012" from the datum to the head of the case.

Short cases are handy when cutting a chamber. I have never said "When cutting a chamber check often because no one knows where they are when completing the chamber". I know the length of the chamber when I start and when I finish and always know how close the chamber is to being completed.

Point? When a full length sized case has been returned to minimum length and will not allow the bolt to close, I form cases for the chamber using the same method and or technique I use to form cases for short chambers.

Using the feeler gage to raise the case off the deck of the shell holder will allow the reloader to determine how short the chamber is. Added benefit, adding the feeler gage between the deck of the shell holder and head of the case increases the presses ability to overcome the cases ability of the case to resist sizing.

F. Guffey

 

I had no intention of criticizing how an individual solved the long chamber issue or forming cases. My point was that factory rifles can have errors. There is a chance that some previous owner tampered with my rifle. My preference is to have a factory rifle that will chamber and satisfactorily fire standard cartridges. Using all this energy to to reform a cartridge case to accommodate a bad chamber is simply not worth the effort to me. The solution, for me, is having the chamber corrected by a competent gun or returning the firearm to the factory for work. I can see having more than one .308 and wondering which batch of cartridges is made up for this rifle.

 

The solution, for me, is having the chamber corrected by a competent gun or returning the firearm to the factory for work. I can see having more than one .308 and wondering which batch of cartridges is made up for this rifle.

The thing is, though, that you can take two rifles of the same model and same caliber, made on the same day and one right the other on the assembly line, and have two chambers that are different. Unless it is so out of spec that its unsafe, don't sweat it.

The whole point of this thread is that you can adjust the sizing without any additional cost so that you don't get head separations. I'm sure we'd all like having a perfect chamber, but even if its a little bit long, or even a little short, you can still use the rifle. You don't need feeler gauges; you don't have to form cases from another caliber; but most of all, you don't have to make it more complicated like certain people here are advocating.

 

Using the feeler gage to raise the case off the deck of the shell holder will allow the reloader to determine how short the chamber is. Added benefit, adding the feeler gage between the deck of the shell holder and head of the case increases the presses ability to overcome the cases ability of the case to resist sizing.

Using all this energy to reform a cartridge case to accommodate a bad chamber is simply not worth the effort to me.

William A. Reed, trouble shooting should fall under the heading of 'Handloading Procedures/Practices' others could call it 'Methods and techniques'. If I have a chamber that is too short I want to know by how much. Shooting formed cases in a rifle with a short chamber is up to the reloader.

Back to 'Handloading Procedures/Practices', I do not assume raising the ram on the press full length sizes the case. It is possible the case has more resistance to sizing than the press can overcome. When the case will not chamber after full length sizing I check to see if the die made it to the shell holder. Like everyone else I have presses that will not overcome the cases ability to resist sizing.

It is possible to size cases that are shorter than a minimum length sized case, it is possible to size a case that is .017" shorter than a minimum length sized case, going the other way it is possible to size a case to a practice 'filed reject chamber length'.

Choices, I will not spend $400.00 dollars for 10 sets of competition shell holders, When determining the length of a chamber on a used rifle I use the feeler gage to adjust the die off the shell holder, I also use the feeler gage to verify the adjustment and I use the feeler gage to determine if the case whipped the press. You do not need a feeler gage, my presses and dies have threads, threads make it possible to adjust the die to the shell holder. I could make wild guestimates when adjusting the die or, I can use the verifying tool, the feeler gage.

F. Guffey

 

If I have a chamber that is too short I want to know by how much. Shooting formed cases in a rifle with a short chamber is up to the reloader. F. Guffey

In your posts that mention "short chambers", are you referring to chambers that are shorter than SAAMI/military specifications?

 

Originally Posted by fguffey View Post
I have absolutely no interest in what those rounds would have done in the other rifle.

Quote:

In your posts that mention "short chambers", are you referring to chambers that are shorter than SAAMI/military specifications?

I do not care if it is a military chamber or a commercial chamber.

Originally Posted by fguffey View Post
Respect for Unckelnick? I believe he is one of the very few that is capable of keeping up.

My, my. You certainly are a legend in your own mind

Keeping up? When problems develop during sizing the reloader should know there is a problem with his methods and techniques, the reloader starts with factory/new never fired ammo. The reloader never measures factory ammo and have no ideal what to expect from full length sized cases. If they had a clue what the length of the case from the shoulder to the case head of new ammo they could use a comparator to determine the difference between minimum length new cases and cases that they believe have been full length sized.

I am a reloader, none of this drives me to the curb or locks me up, other reloaders? If they do not understand 'it', they do not understand 'it', if they can not do it, so be it. It is not my job to tell someone it can not be done.

I measure chamber lengths three different ways, the length of the chamber is not something that is nice to know, for me it is a must know.

F. Guffey

 

I do not care it is a military chamber or a commercial chamber.

Let me restate that: When you refer to short chambers, do you mean shorter than the standard it is supposed to conform to?

In other words, if you has a Remington 700 chambered in 25-06 and the chamber headspace measured 2.040, would you apply your techniques, as described, to make ammunition for that particular rifle?

If you has an M1 Garand that had a chamber headspace dimension of 2.040, would you do the same?

I'm just trying to get an idea of what you are considering a "short chamber" that you would apply your described techniques to.

 

I apologize to all concerned for commenting on short cases. Some of the suggestions don't make sense and my comments complicated the situation. No more from me.

 

Dollar Bill,

I don't think member fguffey is trying to be inflammatory or irritate members. Whatever knowledge he has - it seems he has difficulty expressing it via the written word.

Don't take it personally. Honestly - I can't understand his posts either. It does appear that he can make his own gages. Beyond that.... I do not know.

 

Got it. Thanks. I'll definitely keep it in mind.

 

It is a mistake to assume reloaders are case formers, same for those building rifles. I form cases, I do not fire form, meaning when I go to the range the case fits the chamber from the shoulder to the bolt face. A reloader with a press, dies and shell holders have a problem when forming cases for long chambers, I don't. My favorite chamber is the long chamber from the shoulder to the bolt face, because of the design the Mauser is my favorite receiver for long chambers. I have no problem with other designs but a reloader that does not know what they are doing can get case head separation, again, not my problem, I form cases first then fire.

My favorite case is the case that is too long for the chamber from the shoulder to the case head for the chamber. Then there is product knowledge, I do not fire form cases in rifles that allow the case head to separate, some designs do, some designs forgive the ignorant shooter/reloader.

Ignorant? Is a matter of simply not knowing.

F. Guffey

 

It is a mistake to assume reloaders are case formers, same for those building rifles. I form cases, I do not fire form, meaning when I go to the range the case fits the chamber from the shoulder to the bolt face. A reloader with a press, dies and shell holders have a problem when forming cases for long chambers, I don't. My favorite chamber is the long chamber from the shoulder to the bolt face, because of the design the Mauser is my favorite receiver for long chambers. I have no problem with other designs but a reloader that does not know what they are doing can get case head separation, again, not my problem, I form cases first then fire.

My favorite case is the case that is too long for the chamber from the shoulder to the case head for the chamber. Then there is product knowledge, I do not fire form cases in rifles that allow the case head to separate, some designs do, some designs forgive the ignorant shooter/reloader.

Ignorant? Is a matter of simply not knowing.

F. Guffey

Have you ever had a rifle built with a short chamber, so that all available brass is too long for that chamber, thus allowing you to form the case perfectly?

I have to say: You make it sound as though anyone who just buys factory brass and loads up rounds that function perfectly well in their rifle are ignorant. Perhaps in a sense they are, but to what detriment? If their groups are small and their deer are dead, what does it matter if their brass doesn't last quite as long as yours?

Having been thusly accused myself, it seems that your efforts to share your knowledge are not being well-received, coming across as condescending, at times.

 

Mr. Guffey is actually an experienced gunsmith and toolmaker. He often communicates by contextual rather than linear narrative. My grandfather liked to do that; always a story or example. But Granddad was born in 1890, and you young'n's will likely have less exposure to that style. It doesn't change that there are gems to be mined from what Mr. Guffey writes.

One of Mr. Guffey's repeating themes is the relative nature of the headspace and cartridge fit. The point is to marry them in a way that gets you good precision, and not that either one has to adhere to a SAAMI standard. Folks forget that SAAMI is a manufacturer's standards organization, and not a handloader's standards organization. Everything from their dimensions to their pressures are devised to enable manufacturers of guns and ammunition to make cross-compatible products without either gun or ammunition makers having to sample or test one another's products.

SAAMI is addressing different problems than are faced by the handloader, who has the exact gun and brass and bullets whose physical dimensions need to work together. You can think of the handloader as an 'almost-wildcatter' when he adapts a cartridge to a gun via loading practices. Frequently, in SAAMI standards, you find the smallest size for a rimless bottleneck cartridge shoulder position is about 0.002" back from the size of the smallest specified chamber. So, 0.002" is the loosest fit you can find for a minimum chamber. That looseness feeds and shoots just fine. Indeed, it is actually more than you have to have. Because the case is made narrower than the chamber, it has room to swell, so you can actually have a slightly compressed fit between case and chamber at the shoulder that will still chamber and operate correctly, if a little less smoothly. But that compressed fit is not going to produce the smallest groups.

Evidence, particularly from a lot of work done by the U.S. Army and Navy Marksmanship Units, has shown that a slightly loose fit (0.001" is enough) will allow the tapered shoulder of a cartridge to self-center in the tapered shoulder of the chamber under firing pin force. This produces the best bullet alignment and resulting precision on the target. That slight fit looseness is what "bump" sizing is supposed to maintain. Since a cartridge typically springs back somewhere around 0.001" in length after firing at normal medium power rifle pressures, but gradually grows over subsequent firings, the 'bump' is just supposed to keep the case from growing from that first-time as-fired position. This practice or its equivalent done in standard FL dies has mostly displaced neck-only sizing in benchrest competitions. It seems recognition has grown that the marksmanship unit findings are correct.

All the above means that when you have a chamber that is not a SAAMI minimum chamber, sizing your cases -0.001 to -0.002 back from the size of that chamber will "adapt" the case to that chamber. It creates your 'almost-wildcat' that need not necessarily work in any other gun. The springiness of brass makes a fired case a less-than-exact indicator of the actual size of your chamber. But if you know how to strip a bolt to get delicate feel, and cut shim stock discs to space the case head off the bolt face, and are careful that your feel is delicate enough not to compress the case upon contact with the shoulder, you can find the actual chamber dimension with the fired case and shims as your gauge. You can then do your sizing die setup to get 0.001" to 0.002" shoulder setback from that chamber dimension.

 

Your explanation, unlike Guffy's, is clear, concise, and easy to follow. It doesn't matter how smart or accomplished you are. If you can't communicate that to others in a manner that is clear, concise, and easy to follow, all you do is confuse people. He really needs to work on his presentation, and attitude is an integral part of that.