Fire-forming Brass

[South Pender]

Hi all. I have a bunch of virgin 222 Rem cases prepped (trimmed, turned, uniformed, etc.) and need to now fire-form them in my Cooper M21. I'm wondering whether I should use a light, medium, or stiff load (bottom of the powder-charge range, mid-way, or near the top in a loading manual) to get the cases fully fire-formed to the rifle's chamber. The goal would be to have fairly tightly-fitting cases on the next firing of the cases. Can this be accomplished with a single firing?

Thanks for any recommendations.

 

[CatShooter]

Hi all. I have a bunch of virgin 222 Rem cases prepped (trimmed, turned, uniformed, etc.) and need to now fire-form them in my Cooper M21. I'm wondering whether I should use a light, medium, or stiff load (bottom of the powder-charge range, mid-way, or near the top in a loading manual) to get the cases fully fire-formed to the rifle's chamber. The goal would be to have fairly tightly-fitting cases on the next firing of the cases. Can this be accomplished with a single firing?

Thanks for any recommendations.

Full-ish load and oil the cases with a light oil. They will fill the chamber and not stretch.

 

[mikecr]

+1 CatShooter

 

[bigedp51]

-1 CatShooter

I wasn't going to say anything............................but a picture from the Sierra manual is worth a thousand words.

Be Careful boys and girls many older firearms were not made for this type abuse.

Below from the 1929 British Textbook of Small Arms.

NOTE: The British used the base copper crusher system above and the copper crusher was located at the base of the case. The copper crusher was hollow to allow the firing pin to pass through the crusher and hit the primer and the case had to be oiled to measure the correct chamber pressure. If the case was dry the reading would be 405 TO 50% LESS Because the case gripped the chamber walls reducing the bolt thrust and pressure reading.

And to this day the British test all their military small arms with two oiled proof pressure cartridges. The firearm is then checked for headspace and bolt setback, if the rifle has more than .002 to .003 bolt setback the rifle fails proof testing.

I will accept what CatShooter and other may say about oiling cases to fireform them in "new modern firearms" BUT this can still increase headspace if the strength of the steel is exceeded using high pressure loads.

The Above message was brought to you by the Society for the Prevention of Cruelty to firearms.
(but it's the only disagreement CatShooter and I have, other than who is better looking)

Below is a photo of CatShooter on the right and his younger brother on the left.

And below is my High School Graduation photo before hitting it big in the reloading industry.

Bazinga ;D

 

[jonbearman]

Remember biged bolt thrust doesn't exist. I learned this just the other day.

 

[bigedp51]

Remember biged bolt thrust doesn't exist. I learned this just the other day.

That only happens when shooting low pressure loads and only the primer touches the bolt face.
Because the bolt thrust is so low they need mathematical formulas and computer programs to figure out the miniscule pressure from the primer. And we haven't even delved into the primer dwell time and diameter. :

I have to go now, I'm pounding on fguffey in another forum and he might be crying about that big bad man not being nice to him.

 

[jimcasey01]

bigedp51,
You have a very sick since of humor, and I love it. I can see that I am not alone in this world. Keep on laughing, it keeps us feeling young, even if we are not. ;D
Jim

PS your photo looks vaguely familiar, maybe we have met.

 

[bigedp51]

bigedp51,
You have a very sick since of humor, and I love it. I can see that I am not alone in this world. Keep on laughing, it keeps us feeling young, even if we are not. ;D
Jim

PS your photo looks vaguely familiar, maybe we have met.

My father was a retired Navy Chief, I grew up in the military, I served in the military and worked for the military after getting out of the military..................
And I have a beautifully warped military mind.

Below are some of my Naval fathers early indoctrination training.
(my father was an airedale and hated anyone whose stripes were not Naval Aviation green, meaning deck apes and snipes)

How many sides to a ship

There are seven sides to a ship
1. Portside
2. Starboard side
3. Topside
4. Bottomside
5. Inside
6. Outside
7. And come along side.

And for the rest of the forum members I qualified as a expert marksman in the military.
Out of a possible 60 rounds in my target I had 87 bullet holes in my target.
(you bench rest shooters can eat your hearts out)

 

[Brians356]

Fireforming with a lubed case is perfectly safe - if you are fireforming "bulletless". A trace of light lube (ala Rem Oil) is superior for bulletless forming of an improved case.

OP, what wildcat are you forming from 222 Rem? If it's just a 222 chamber, any reasonably stiff load will do, it only has to expand the brass a paltry few thousandths. What am I missing here?

 

[South Pender]

OP, what wildcat are you forming from 222 Rem? If it's just a 222 chamber, any reasonably stiff load will do, it only has to expand the brass a paltry few thousandths. What am I missing here?

Not forming a wildcat, just fire-forming some virgin 222 Rem. cases in a 222 Rem. chamber.

 

[bigedp51]

Hi all. I have a bunch of virgin 222 Rem cases prepped (trimmed, turned, uniformed, etc.) and need to now fire-form them in my Cooper M21. I'm wondering whether I should use a light, medium, or stiff load (bottom of the powder-charge range, mid-way, or near the top in a loading manual) to get the cases fully fire-formed to the rifle's chamber. The goal would be to have fairly tightly-fitting cases on the next firing of the cases. Can this be accomplished with a single firing?

Thanks for any recommendations.

South Pender

Learn the Ewok dry method and just don't listen to your rifle screaming in pain.

Take a fired spent primer and seat the primer in your new cases with just finger pressure.

Now chamber this test cartridge and slowly close the bolt letting the bolt face seat the primer. Now measure how far the primer is protruding from the rear of the case and this will be your head clearance.

If the head clearance is approximately .004 or less then just load the case and fire normally. If the head clearance is excessive you can seat your bullets long and "jam" the bullets into the rifling with a mid range load. The jammed bullet will hold the base of the case against the bolt face and the cases will not stretch.

P.S. Don't tell Fguffey about the primer method because he will cry knowing his datum point rambling postings will be dead in the water and headspace will have a all new meaning.

So fireform dry after you know your head clearance and then wet your whistle when your done.

 

[CJ6]

Send me the one in the middle....or a case or 2....

 

[CatShooter]

-1 CatShooter

"Mike Ratigan, National and World Champion short range BR, in his book "Extreme Rifle Accuracy" advocates lubing the case with light oil because in his words: "When the case starts to pressure up, it won't grip the sides of the chamber because of the oil" He goes on to say "This will allow the case to be forced back up against the bolt face and it will stay there without stretching the web area...."
I was taught by some very good mentors, multiple IBS record holders, to lube the cases.
Remember to swab out the chamber after FF. Comparing lubed FF cases with those FF dry, there is a big difference in finish case length and consistency."

Of course none of the above applies to you if you shoot 100 year old junkers.

But any modern rifle (including Coopers) will do fine.

 

[CatShooter]

Remember biged bolt thrust doesn't exist. I learned this just the other day.

Jon... you're an intelligent person.

Think about it.

Thrust is something that comes from sources of energy - engines develop thrust. Propellers develop thrust. Wheels develop thrust (when connected to an engine and drive train).

Bricks do not develop thrust. Bolts do not develop thrust.

Cartridges generate energy and develop thrust, trying to get out the back of the chamber - the bolt restrains the case. The bolt does not develop thrust - it is thrust upon by the case.

Words have meanings, misuse of words hinder the understanding of what is being said.

 

[bigedp51]

CatShooter

I learned a lot from my 100 year old junkers and the British used the base crusher system for measuring chamber pressure.

If the case was dry the the copper crusher would only read half of the chamber pressure, and the case would only deliver half the bolt thrust to the face of the bolt.

Now do you actually think that just turning the bolt increases the headspace over time or is it caused by the bolt getting slammed by 50,000 psi when you pull the trigger.

A dry case acts like a shock absorber and reduces bolt thrust and the dwell time the case pushing on the bolt face. The British were not stupid, they were being cheap and used lower grade steels to make their military Enfield rifles and used replaceable bolt heads to adjust headspace.

And this CatShooter is what I have against lubing cases, people come to forums like this and some young kid reads a posting about lubing cases and it ends up filtering down to milsurp forums. The next thing you know people are pounding the crap out of these older rifles because of the brilliant advice they got from the big boys.

Now you think about it, proof pressure testing with oiled cartridges can and will increase headspace.

And P.O Ackley removed the locking bolt from a Winchester 30-30 rifle and test fired the rifle with a "DRY" chamber. The rifle did not blow up, the dry case gripped the chamber walls and the only thing that touched the bolt face was the backed out primer.

Measuring Cartridge Pressures

In Britain, a third set of crusher standards were developed, using a "base" crusher. The crusher was a short, thick tube placed behind a piston at the base of the cartridge, and the firing pin passed through the center. The cartridge case was well oiled before firing, to minimize cling to the chamber walls (if not oiled, the indicated pressures were about 25% lower). To prevent case rupture on set back of the base, the crusher was first deformed in a press to a pressure a bit lower than that expected in firing. The units were generally stated in British long tons per square inch, or tsi.

http://kwk.us/pressures.html

Below is from the H.P. White testing Labratory

Now CatShooter think of the bolt and receiver as the Space Shuttle and the cartridge as the shuttles rocket engine.
The Space Shuttle got into orbit from the "thrust" provided by its rocket motor and a oiled case is trying to push the bolt into orbit.

And old rifles can teach old dogs new tricks.

And the No.4 Enfield rifle used upgraded EN grade steel and was later chambered in .308/7.62 and still had replaceable bolt heads.

Now smile CatShooter, how many of your forum buddies have a Crocodile Dundee Magnum Roo light and Koala Bear targets. ;D

Now look at the cats paws below and lean into the computer screen.....................do you feel the thrust?

 

[Shynloco]

Hey bigedp51,
Regarding your graduation photo, did you by any chance change your hairstyle?

Alex

 

[riflewoman]

All joking and kidding aside, a very light coat of oil will allow the cases to fire form and fill. There will be a slight increase in bolt thrust but the case will not grip the chamber so the increase is only that from the elastic reaction from the case. Remember, the case walls have yielded and are expanded plastically in all directions so the pressure is acting on the case head with all the force it can muster. This goes to the bolt face. So your 60000 psi is acting on the bolt face eventually.all your doing with a light coat of oil is not allowing the case to yield before it happens. And by light coat of oil all that is required is a very quick wipe with a gun oil soaked patch, not dripping.

As far as oiled cartridges increasing headspace that is a function of poor construction and steels. As a result of proofing the Lee Enfield chambers also swelled to their enlarged condition. Also the Lee Enfield removable bolt heads were to allow armorer's to adjust headspace in the field. The rifle could not be delivered from the OEMs if it had a bolt head higher than 1 except in wartime.

 

[mikecr]

bigedp51, great info, and funny too!
I agree with CatShooter because it's practical in this case.

I've jammed & false shouldered(preferred), but in some cases it's not practical(non-wildcat factory chamber) or possible(to jam). He said full-ish load, meaning -not a hot load, because he's aware of additional bolt forces with this.
It was not implied here that oil in the chamber is routinely acceptable, but useful in this case.

You know this bigedp51, but for the newer reloaders;
We don't want cases to stretch back to the bolt face on fire forming. We want case heads against the bolt face and shoulders blowing forward.
Cases stretch back because they expand first at the neck, and body-shoulder junction, and then working back to a web line. So on firing there is a timing point where the forward half of a case grips the chamber while the back half is still free to stretch. Repeated cycles of this leads to thinning near webs, and eventual case head separations. It's considered dangerous in that a case head slamming the bolt is hitting more like a hammer strike than a normal push.

Where you have excess head clearance(a new case) bullet jamming is only somewhat effective to keep a case head against the bolt face. Primer striking/firing can push the bullet deeper into rifling & neck, and the case shoulder wedges into chamber shoulder, and now head clearance has increased(defeating bullet jamming method) to pretty much max.
A false shoulder of high enough angle can mitigate this forward movement on firing. But this is a little more advanced than covered in most books. It takes more planning & tools & efforts, that someone creating a wildcat cartridge would go through(they enjoy it).
Then there is lightly lubing new cases for standard fire forming -a bit under full load. This is minus 1-2gr from book full load with a 222. Just as you would back off to begin with any component change or new/unknown condition.
On firing the case would wedge forward but can't grip itself there, so firing pressure will drive the case back against the bolt face in an offending but managed way. Now the shoulder can blow forward, fully forming to your chamber without stretching of the body.

Now with fire formed cases you keep your chamber/cases dry, and your sized head clearance very low(within 1-2thou).

 

[bigedp51]

As far as oiled cartridges increasing headspace that is a function of poor construction and steels. As a result of proofing the Lee Enfield chambers also swelled to their enlarged condition. Also the Lee Enfield removable bolt heads were to allow armorer's to adjust headspace in the field. The rifle could not be delivered from the OEMs if it had a bolt head higher than 1 except in wartime.

Where do you people come up with this bovine scat?????

The No.4 Enfield rifle was made from EN grade steel and were later chambered in .308/7.62 and 52,000 cup chamber pressure. The earlier No.1 Enfield rifles were made of a lower grade steel and could not be rechambered to .308/7.62 without damage at the higher proof test pressures. The Australians perfected the conversion of the No.1 Enfield to .308/7.62 by using higher grade steels in the receiver and bolt and improved heat treating. These conversions were over half the cost of the No.1 Enfield rifle and were not carried out by the Australians and new L1A1 (FAL 7.62) were purchased over a longer period of time. The Indians at Ishapore did make these conversions to the No.1 Enfield rifle with EN grade steel and the rifle was called the 7.62 2A1.

The chambers were larger on the Enfield rifle because they were reamed larger in 1914 because of the muddy dirty conditions of trench warfare. "AND" because of the Government ammunition scandal over poorly made ammunition not chambering in the rifle. Ammunition manufacturing contracts were awarded because of cronyism to companies that had never made ammunition before.

Proof pressure testing does NOT make chambers larger in diameter but the added bolt thrust could increase headspace.

So one more time, a rifles headspace increases over time because of the pounding the bolt lugs and receiver lug recesses are subjected to when fired and the bolt thrust on the lugs.

And to this day all British small arms are proof tested with two oiled proof cartridges and if the headspace increases over .002 to .003 the firearm fails proof testing. And American commercial firearms are proof tested with one DRY proof cartridge which does not subject the rifle to as much bolt thrust.

If your going to make comments about the Enfield rifle then you should buy more books on the subject and do a little reading.

I also had a Springfield 03-A3 that failed the field headspace gauge test so bolt thrust and headspace covers ALL firearms and not just the Enfield rifle.

 

[bigedp51]

dmoron

I didn't give you permission to copy my photos and images in my posting, I'm going to bring a lawsuit against you for being such a anus orifice.

(Gee that sounded just like the PM dmoron sent to me)

You really need to get a life and pull your head out of your backside.

Have a nice day ;D