case separation

[bloc]

Question: does anyone still use the old trick of taking a piece of straight wire, bending it about ¼ inch from one end to 90 degrees, and feeling the inside of the case for a groove at the case's head/body transition (it was once said the groove would indicate incipient head separation)?

I check every case. Am I alone?

 

[mr45man]

One of these come in handy around the reloading bench
http://www.cycleworld.com/2011/03/30/graham-tools-fiber-optic-adaptor-tool-time/
John H.

 

[bigedp51]

1. If you buy the Hornady cartridge case headspace gauge you will not need to buy a Wilson type gauge or the RCBS precision mic for every caliber.

Since I purchased the Hornady cartridge case headspace gauge, I no longer use my precision mic and I use my Wilson case gauges as paper weights and pen holders.

Did I tell you to buy a Hornady cartridge case headspace gauge?

2. I no longer use the bent paper clip trick for checking stretching and thinning of my cases, I use the RCBS case mastering gauge.

Below is a factory loaded once fired Winchester .303 British case that stretched and thinned .009 on its first firing.

The first firing of your case is critical and using the primer method for checking your chambers and cartridge headspace I mentioned before will tell you how much head clearance you have.

You will then need to decide on what method you are going to use to fire form your cases.

 

[bloc]

Bigedp51 . . . Those are terrific pictures. Extremely instructive.

I actually have several Precision Mics, Wilson gages, and the Stoney Point comparator (the precursor of its Hornady incarnation . . . before Hornady added the headspace gage). I use them all.

But I also use the bent-wire technique as a way to discard cases before head separation might occur. (I neck size perhaps 70% of my cases, but bent-wire-check all of them, and in several decades of reloading I've found only one that I needed to discard. I've never had a head separation.)

Looking at your pictures (are you a pro?) I'm struck by the photos under your number 2, especially the one with the red arrows (2., third photo).

The top arrow is aligned with the groove it is my goal to feel with a bent wire, and I have a question: what advantage do you find using the RCBS case measuring capabilities over the simple bent-wire/bent-paperclip method that I've been using?

I ask because I find the bent wire method very quick and sensitive . . . but if I'm missing something that the RCBS case measuring gauge would give me that my bent-wire technique does not, I'd buy one in a heartbeat.

Thanks.

 

[bigedp51]

The best trick isn't the bent paper clip or the RCBS case mastering gauge, the real trick is not letting the case stretch in the first place, meaning proper fire forming.
We all used the bent paper clip method in the past but the RCBS gauge is more precise and tells you within a thousandths of an inch how much the case has stretched and thinned.

Bottom line, using the spent primer method to determine head clearance tells you ahead of time the distance from the rear of the case to the bolt face, and how far the case will stretch.
Then "YOU" decide the best method for fire forming and preventing the case from "stretching in the first place".

If your lucky enough to have a British .303 Enfield rifle then fire forming your cases is very easy. You just slip a thin rubber o-ring over the case to hold the cartridge against the bolt face.

Then all you need is half a Mossberg shotgun, a seat belt off a 1964 Rambler and your ready for locale benchrest competition and still have a end of the world SHTF sniper rifle. :

bloc, you asked if I was a pro and the answer is yes, I'm a professional golfer and I play in the low 70s, if it gets any hotter than that I don't play. (I then stay in the clubhouse and drink beer to stay cool)

But just remember excess headspace can happen any time, even in the club house.

 

[CatShooter]

If your lucky enough to have a British .303 Enfield rifle... [...]

This is actually a secret code phrase to the dark side of the internet, the "Dark Net", and a test on your understanding of the converging forces of the universe, leading to the date of the final impending solar confluence.

 

[jds holler]

It is quite understandable that reloaders of the 303 Brit cartridge would have a much deeper understanding of head space issues than other mortals. jd

 

[CatShooter]

It is quite understandable that reloaders of the 303 Brit cartridge would have a much deeper understanding of head space issues than other mortals. jd

In fact, there is a whole industry in Birmingham devoted to .303 Brit headspace. They offer 793 different headspace gauges for the .303 Brit.

 

[jds holler]

While this is new information to me, it doesn't surprise me in the least. jd

 

[Patch700]

It is quite understandable that reloaders of the 303 Brit cartridge would have a much deeper understanding of head space issues than other mortals. jd

In fact, there is a whole industry in Birmingham devoted to .303 Brit headspace. They offer 793 different headspace gauges for the .303 Brit.

Lol... As opposed to the other industry there that offers left over pencil erasers to be used as Enfield "Ejector spring updates" lol.

 

[TikkaSporter]

Just a shot in the dark, but I suggest also checking your cases for donut issues, leading to increased pressure, leading to case head separations...

I was bit by this once, resulting in 2 case head separations before I figured out what was happening. Once moderate loads started randomly showing pressure signs without a change in powder or primer lots... Backing the load down helped temporarily, but the random pressure signs would eventually come back until finally it resulted in a case head separation. I sectioned several cases from that lot of brass and saw no significant thinning near the web so concluded it was a random fluke... 20 rounds later it became apparent it was no fluke...

Finally tried dropping a bullet down the necks of fired cases from this lot of brass and they slid right in UNTIL the bullet ogive above the boat-tail hit the neck-should junction, where is stopped abruptly. No amount of hand force was enough to push the bullet past the donut, yet I could barely detect the increased seating force with the mechanical advantage of the reloading press.

New brass and the problems went away, pressure signs disappeared, and accuracy was restored at the original powder charge.

Also IMO, the best way to see case thinning at the web is to section a suspected case and look at it from the inside.

 

[CatShooter]

Just a shot in the dark, but I suggest also checking your cases for donut issues, leading to increased pressure, leading to case head separations...

I was bit by this once, resulting in 2 case head separations before I figured out what was happening. Once moderate loads started randomly showing pressure signs without a change in powder or primer lots... Backing the load down helped temporarily, but the random pressure signs would eventually come back until finally it resulted in a case head separation. I sectioned several cases from that lot of brass and saw no significant thinning near the web so concluded it was a random fluke... 20 rounds later it became apparent it was no fluke...

Finally tried dropping a bullet down the necks of fired cases from this lot of brass and they slid right in UNTIL the bullet ogive above the boat-tail hit the neck-should junction, where is stopped abruptly. No amount of hand force was enough to push the bullet past the donut, yet I could barely detect the increased seating force with the mechanical advantage of the reloading press.

New brass and the problems went away, pressure signs disappeared, and accuracy was restored at the original powder charge.

Also IMO, the best way to see case thinning at the web is to section a suspected case and look at it from the inside.

You must have missed something along the way, cuz head separations are never caused by pressure (or donuts).

If you had donuts, that is a separate problem, but head separations are only caused by cases stretching from headspace problems.

 

[bigedp51]

It is quite understandable that reloaders of the 303 Brit cartridge would have a much deeper understanding of head space issues than other mortals. jd

In fact, there is a whole industry in Birmingham devoted to .303 Brit headspace. They offer 793 different headspace gauges for the .303 Brit.

Dear CatShooter, you long haired (expletive deleted) commie pinko pervert)

There are only two headspace gauges for the British Military Enfield rifle and the American SAAMI added the middle one below to confuse Americans.
The British also do not use the middle SAAMI headspace gauge and their football players do not wear protective head gear.

It is quite understandable that reloaders of the 303 Brit cartridge would have a much deeper understanding of head space issues than other mortals. jd

Anyone who owns a Enfield rifle and does not have case head separations is in direct contact with the Greek Gods and is no longer a mere mortal.

P.S. I only added the Enfield information to make Boyd Allen's blood pressure go off scale. :

P.P.S Addition reading requirements below.

Also many of you here in this forum should learn how to vent and not become frustrated.

NOTICE: No Enfield rifles were hurt or injured during the filming of this posting.

 

[bloc]

bigedp51: Thanks for the rationale: I agree that the best way to prevent head separation is to properly size your brass in the first place. I myself have never had a head separate, but I did discover one piece of .270 brass with a thinned case which I pitched. Haven't tried the fired-primer trick, but it sounds useful and absolutely fool-proof.

FWIW — I once replaced a batch of .270 brass even though I had no reason to believe any of it was in any way flawed. But I'd reloaded the cases a dozen times, and I'd read about people discarding brass after 8 - 10 reloadings because they (people) started having case separations, and I wanted to be better safe than sorry.

Thanks to you and all for a fascinating discussion.

 

[CatShooter]

FWIW — I once replaced a batch of .270 brass even though I had no reason to believe any of it was in any way flawed. But I'd reloaded the cases a dozen times, and I'd read about people discarding brass after 8 - 10 reloadings because they started having separations, and I wanted to be better safe than sorry.

Thanks to you and all for a fascinating discussion.

In 1975, I bought a Remington 40-XB single shot in 22-250 w/ a 2 ounce trigger, and a Lyman Super TargetSpot (for all of whoppin' ~$600)... and I bought 400 pieces of Winchester brass.

I "broke in" the brass properly, and it went though 5 barrels in 22-250, until I had the rifle rebarreled for the 6th time in 244 Rem. I annealed every 4 to 7 loadings, and only FL sized them twice when changing barrels that had tighter chambers.

I had loaded those cases ~45 times each, and I lost a bunch in tall grass, but I never lost one to a head separation or a split neck.

When I rebarreled to 244 Rem, I had sworn off of the 22-250, so I tossed the brass.

About three years, I would up with another 22-250 (a 700 VSF). I bought new Lapua cases for it... they will outlast the barrel.

If you take care of your brass, it will show you the appreciation.

 

[bigedp51]

bigedp51: Thanks for the rationale: I agree that the best way to prevent head separation is to properly size your brass in the first place.

1. The best way to prevent case head separations is to not let it stretch on the first firing.
2. The second best way to prevent case head separations is minimum shoulder bump when full length resizing.
3. The best way to study case head separations is to buy a $69.95 Enfield rifle and shoot Winchester brass.

But then again how many forum members have a Paul Hogan (Crocodile Dundee) Magnum Roo light "AND" a Enfield rifle?

(NOW BACK IN THE SERIOUS MODE)

We also live in a plus and minus manufacturing world and no two dies are exactly alike and the quality of our cases varies.

The test below was done with a brand new Savage .308 rifle and the resizing die adjusted per the the dies instructions and the press reaching cam over.

 

[BoydAllen]

The fellow that I got my SMLE from explained what I have copied and pasted below. He measured his rifle's headspace, noted that it needed correcting, and found the correct bolt head to do that. Consequently it has not have headspace or head separation issues. Of course after a case if fired the first time, I set the FL die to limit its forward movement during subsequent firings. Bottom line, if you do the required gunsmithing, no O rings are required.

"True, the headspace gauges used by the British military is a bit longer than SAAMI specs. I think the NOGO for SAAMI is 0.067 while the military one is 0.070. The military FIELD gauge is 0.074. Recall, this is the distance from the boltface to the rim.

The boltheads for #1 MKIII are not numbered. They made one size bolthead (longer) and the armorer needed to sand one down to get the correct headspace. So, fixing the headspace cannot be done in the field.

This problem was cured when #4 MK1 was introduced. The boltheads were made in 4 different lengths with 0.003" increments. They were also numbered from 0, 1, 2 and 3. Some people say that there are number 4 and 5, but they are next to impossible to find. On top of that, a rifle that needs bolt head number 4 or 5 is already due for a barrel replacement or just turned into a wallhanger.

BTW, the boltheads for #4, AFAIK, do not work for #1."

 

['Freak]

I didn’t invent nor discover a thing about this whole mess of vibrations going on about a rifle barrel as well as everything that’s in physical contact with said barrel, every time a round gets fired in the thing. The vibes begin with the mechanicals letting loose of the firing pin and it lighting off a big boom within the case. Those vibes are then transmitted onto everybody else with each of the vibe patterns mixing with, adding to, and/or somehow being affected by all the other vibes that were initiated and/or encountered along the way as they all run back and forth until completely dissipated.

I’ll contemplate the how come and what ifs of lots of stuff and will try some stuff all on my own, but I won’t preach something as being good or bad or how folk might deal with anything, until I’ve seen it either work very well, or heard and/or read where somebody else far more qualified than I and whose opinion is well respected by many of their peers, verifies something is so where I had only figgered that might be the case.

Example being, I’d never seen the phrase “case harmonics” until #35, but have seen this:

“Neck sized cases will over the course of two or three firings; not only becoming quite tight in the chamber, but will do so to varying degrees, leading to inconsistent bolt operation and inconsistent barrel harmonics. A fired case hits the inside of the chamber hard enough to initiate an element of the barrel's vibration pattern; do that inconsistently and your accuracy will suffer.”

Or so says some yahoo going by the name “Germán A. Salazar” in this article:
http://riflemansjournal.blogspot.com/2010/06/basics-resizing-case-dimension-changes.html


Calipers work fine for assessing base to shoulder datum length with the aid of a Wilson case gauge when it’s used in the same manner as a Stoney Point, Hornady, or Sinclair gauge insert, long as you read from the case base and are not reading from the high step of the Wilson gauge.

I do use neck dies but only where the first firing or two leaves new brass still a bit short of completely filling the bolt face to shoulder datum length of the chamber. Once it fills the chamber, thereon I FL size and set the shoulder back minimally to maintain at least some and up to ~ .002” bolt face to case base clearance. Brass maintenance is easier, no excessive working of the brass, and no varying stress levels from closing the bolt on an assortment of too long cases.

 

[bigedp51]

1. The British headspace requirements for the No.1 and No.4 Enfield rifle are .064 minimum and .074 maximum. The problem with the Enfield rifle is "NOT" headspace, the problem is Lake City does not make cases for the .303 British. Meaning the SAAMI standards for chamber dimensions, case dimensions do not apply to military rifles.

2. The No.1 Enfield rifle was inspected four times a year by the unit armourers and if the rifle failed the .074 headspace gauge the armourer fitted a new bolt head.

3. The No.4 Enfield rifle did not solve fixing headspace issues because the bolt head still required proper fitting by the unit armourer. Meaning you just didn't screw on a new longer bolt head and call it done.

4. Bolt head timing was a requirement when fitting a new bolt head, meaning the rear of the bolt head was to contact the collar on the firing pin at the approximate 3:00 position and not over rotate the 12:00 position. This affected the amount the cocking piece is pushed to the rear and also affected trigger pull.

The British military experimented with No.4 and No.5 bolt heads, BUT it was found that by the time anything over a No.3 bolt head was needed the surface hardening of the receiver had been worn through and the receiver needed to be replaced. (It had nothing to do with replacing the barrel) The bolt heads were numbered 0 through 3 and each numbered bolt head was approximately .003 longer than the next size bolt head. This means the receiver lug recesses would have .012 wear and the receiver would be replaced.

And since you can no longer find No.3 bolt heads that do not cost a arm and a leg, and at the maximum headspace of .074 you can have over .016 head clearance the rubber o-rings come in very handy.

Anytime you want to maintain and shoot a accurate Enfield rifle Boyd Allen just ask me, I have all the manuals and spent hours talking to Enfield armourers.

Now go ahead Boyd Allen and tell me a accurate Enfield rifle isn't a accurate shooter and doesent belong at Accurateshooter.com.

 

[BoydAllen]

Mine has this "charming" but solid scope mount, homemade. Back in the day, with an old 4x scope, after I figured out that FL sizing was making my brass crooked, and I figured out how to improvise a neck die with a .300 savage FL die, I worked up a load with the 180 grain Sierras that I had bought a couple of hundred of at a gun show in the bottom of a one pound coffee can, and managed to shoot a five shot group that measured just under an inch, from a good bench, at 100 yards. Thanks for the offer, but I think that I have this one figured out. If I really want to spend some time with it, I will have a friend cut down a FL die into a body die, and buy a Collet die set to do the necks (or continue with the Lee .300 savage die). It has been my observation that cases come out of body dies, (or bushing dies without bushings) about as straight as they went in, and for unturned necks, collet dies do the best that I have seen. This is not likely to happen any time soon since I have a Swedish Mauser that is more accurate than that with the right loads and issue sights.