ejector marks

[Deleted member 46119]

I'm in the process of developing a copper bullet load for my Weatherby 7mm. Using the Barnes 150 gr TSX, I loaded up 3 bullets each of IMR 7828SSC.(My rifle loves that powder...) starting at 72gr up to 74.5 gr in .5 gr increments. My primers are Remington 9 1/2M. While my primers never showed any fatigue, I started to get really faint ejector marks at 73gr and increasing more visible with each progressive load. They were quite obvious at 74.5 gr. Bolt lift and cartridge ejection, however, never changed. It was the same as it always has been and the shells showed no sign of fatigue either. Should these ejector marks be a concern?

If the action is a Weatherby (Mark V or Vanguard), you won't see bolt lift problems until you are practically melting your brass in the chamber.

All my "factory" Weatherby ammunition shows an ejector mark.

My most accurate Weatherby + Barnes loads are far from the lands and going fast. If it's not accurate, I go faster until it gets worse or the ejector marks are worse than factory.

I've never lost a primer pocket. I have never stretched the case forward of the belt. I have purchased "proof" brass where the case was stretched forward of the belt. An Innovative Technologies - Reloading Equipment collet die fixes that and the primer pockets are fine.

It is not a "good" practice to load to pressures that cause ejector marks but many hunters do.

Correlating between longer seating and how much powder to add is something to consider. How much above "book" to have the same pressures yet increased velocity and accuracy. That is of course the challenge.

Good luck and be careful.

 

[bigedp51]

Ejector marks, base expansion and reading primers are all "ball park" guesstimates of chamber pressure. Brass hardness, case construction in the base, primer cup thickness and hardness govern visual indications of chamber pressure.

I have had factory loaded Federal .223/5.56 cases with over sized primer pockets after the first firing. And this was caused by thin flash hole webs and soft brass.

Below CatShooter did some Rockwell testing of brass hardness. And I can tell you a load in Lake City 5.56 cases without any ejector marks will show on softer cases.

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests « Daily Bulletin

Below is a chart from the Lucky Gunner
http://www.luckygunner.com/labs/5-56-vs-223/

Above the left green bar is a factory loaded .223 just below 50,000 psi. And the .223 is rated at 55,000 psi and shows that the vast majority of factory ammunition is loaded "below" maximum rated chamber pressure.

 

[Rich Coyle]

When the fad of measuring case head expansion with blade micrometers emerged from the swamp of ignorance came to light, I was one of the original Dumb Bunnies that ran out and bought one - a new top quality Starett (cuz who would be dumb enough to have a used one in stock).

But I quickly learned the folly of my new toy... well not so quickly, cuz it caused me to waste a lot of time and bullets.

The problem is, case heads vary in hardness, A LOT!!!

Lapua, and Lake City cases have heads with a Brinell hardness (scale "B") around 80 to 90 ( measured them)... Remington and Hornady run 45 to 50-ish (I measured them too).

So, a load that is fine in your Lapua, LC, or Norma cases, will squish the heads of Remington and Hornady cases, giving your nifty blade micrometer a heart attack... yet the loads are fine and safe.

The second problem with using case head expansion for a "pressure indication" is that the pressure actually "thumps" the case head with 3,500 to 5,500 pounds (real pounds, not psi) of pressure, so each reloading, increases the hardness of the head.

Anyone wanna buy a nifty new (almost) Starrett 0-1" blade micrometer? Hardly used, in a beautiful case.

We must be twins. Now I load to get the most accuracy and velocity with at least a few reloads. I back off if there is even the slightest ejector mark. Not because I think it is unsafe because I don't. The last time I went to the range I noticed a "12" with a black felt marker on the cases. That indicates twelve firings on these Winchester cases. This particular rifle is the most gentle on the cases I ever had.

 

[bigedp51]

So, a load that is fine in your Lapua, LC, or Norma cases, will squish the heads of Remington and Hornady cases, giving your nifty blade micrometer a heart attack... yet the loads are fine and safe.

CatShooter

The blade micrometer doesn't need to have a heart attack but the reloader needs to know he has exceeded the elastic limits of the brass. Brass flow into the ejector or base expansion means the brass does not like this high of chamber pressure.

Inflating my cars tires to a higher pressure gives me better gas mileage, "BUT" it wears the center of the tires tread and decreases tire life. Meaning why over stress the brass to the point of brass flow and exceeding its elastic limits and shorten case life.

The photo below came from Accurate Shooter reloading forum and was about "brass hardness" when you posted your hardness tests, The person who posted this photo said he increased the load until he got brass flow into the ejector and then backed 1 or 2 grains. Meaning he tested the brass elastic limits and then kept below this pressure point to make the brass last longer.

There is a reason why cheap bastards like me buy once fired Lake City brass, Its the hardest brass made.

 

[CatShooter]

CatShooter

The blade micrometer doesn't need to have a heart attack but the reloader needs to know he has exceeded the elastic limits of the brass. Brass flow into the ejector or base expansion means the brass does not like this high of chamber pressure.

Inflating my cars tires to a higher pressure gives me better gas mileage, "BUT" it wears the center of the tires tread and decreases tire life. Meaning why over stress the brass to the point of brass flow and exceeding its elastic limits and shorten case life.

The photo below came from Accurate Shooter reloading forum and was about "brass hardness" when you posted your hardness tests, The person who posted this photo said he increased the load until he got brass flow into the ejector and then backed 1 or 2 grains. Meaning he tested the brass elastic limits and then kept below this pressure point to make the brass last longer.

There is a reason why cheap bastards like me buy once fired Lake City brass, Its the hardest brass made.

The actual pressure reached in modern cartridge cases, when used in modern rifles, is not important.

There are three points where pressure can reach the mechanical limits and become a real problem.

1 - The head expansion (ejector extrusions, enlarged primer pockets, "Blown" primers).

2 - The Web (causing "Clickers").

3 - The primer itself (true cratering).

What the actual pressure is when you see these problems is of no concern - you drop the charge or go to another powder.

The rest of the case acts like a semi-rigid brass "bag" to hold things together and make for an efficient delivery system.

All the other problems with cases (head separations, primer flattening, case growth, splitting necks), are due to operator error, and improper FL sizing.

Improper FL sizing is the number #1 cause of handloading problems, and short case life.

 

[Deleted member 46119]

...The rest of the case acts like a semi-rigid brass "bag" to hold things together and make for an efficient delivery system.
...
Improper FL sizing is the number #1 cause of handloading problems, and short case life.

I have used the "balloon" analogy but I like your "semi-rigid brass bag" analogy very much.

I have had problems with Hornady brass that has not been annealed. Once annealed it is fine brass. A bit hard but that is good. Failure to anneal and it seems like the shoulder is work hardened with the first firing so that when FL sizing at all, it is over working the base/web/body junction. Results case separation. Multiple firearms, multiple reloaders (humans), multiple calibers. Same result except the one caliber that was neck sized only with a Lee collet sizer.

 

[paul105]

The actual pressure reached in modern cartridge cases, when used in modern rifles, is not important.

There are three points where pressure can reach the mechanical limits and become a real problem.

1 - The head expansion (ejector extrusions, enlarged primer pockets, "Blown" primers).

2 - The Web (causing "Clickers").

3 - The primer itself (true cratering).

What the actual pressure is when you see these problems is of no concern - you drop the charge or go to another powder.

The rest of the case acts like a semi-rigid brass "bag" to hold things together and make for an efficient delivery system.

All the other problems with cases (head separations, primer flattening, case growth, splitting necks), are due to operator error, and improper FL sizing.

Improper FL sizing is the number #1 cause of handloading problems, and short case life.

What is a "Clicker"?

TIA,

Paul

 

[CatShooter]

What is a "Clicker"?

TIA,

Paul

YWIA

The area of the case, right AT the junction of the case head/web, and the body wall is quite hard. It will flair out slightly on firing, but does not spring back when the case walls spring back.

Each firing causes it to flair a little more. Eventually, it is tight against the chamber wall at the rear of the chamber.

When it gets large, it will resist extraction because it kind of "Stuck" in place. You lift the bolt and the handle comes up easily, until it reaches the top of it's arc. Then it stops, and needs more effort to open - so you life harder and the bolt goes "CLICK" as the case breaks free.

In a normal chamber, a FL die will squish this little ring back in place

If you have a minimum chamber, which is typical with match chambers, or chambers that are cut with old reamers, the base diameter is small - at minimum SAAMI.

The average FL die is a little loose at the base, so it doesn't size this part of the base. So you get clicks and don't know why or where they came from - the case becomes a pain in the *** and you throw it away.

What is needed is a "Small base die" It will squish the base ring and stop the clicking.

If you can't get a small base die int he calibre you have, you can sometimes fake it - if you have a case based on the common 0.473" head size, you can use a carbide 45 ACP die, and size the base

I hope this makes sense - if not, just ask again.

 

[paul105]

THanks for the explanation.

What would be the cause with new brass -- Norma 30-378 for example.

Thanks Again,

Paul

 

[CatShooter]

THanks for the explanation.

What would be the cause with new brass -- Norma 30-378 for example.

Thanks Again,

Paul

??... technically, clickers can't happen with new brass, cuz the definition is a swelling from firing.

But, it could conceivably happen if the chamber was cut so small that the rear of the chamber was 2 or 3 thou smaller than the head of unfired case.

 

[bigedp51]

What is a "Clicker"?

TIA,

Paul

Reloaders like CatShooter get "Clickers" because he neck sizes and loads his cases too hot.............

And smart, good looking and modest people like myself who full length resize and don't over stress the brass never have "Clickers".

P.S. CatShooter......................Bazinga

NOTE, A "Clicker" is also the doohickey on top of your pen.

Below any of the neck sizing dies can be "clickers". And the best dies are the Forster full length benchrest dies with the high mounted floating expanders.

So again "Clickers" are cases with a fat *** that binds in the chamber on primary extraction or lifting the bolt handle.

 

[Barrelnut]

Biged,

I respectfully disagree (and not talking about your intelligence or looks).

I have seen the exact problem CatShooter is talking about on a 300 RUM with a match chamber. The brass was never neck sized only FL everytime. I swear.

It has to do with an off the shelf die not resizing the brass enough right at the junction where the web ends and the standard wall of the case begins. The only way to fix it is to have a set of dies matched to the chamber. Which basically is a small base die.

 

[CatShooter]

Biged,

I respectfully disagree (and not talking about your intelligence or looks).

I have seen the exact problem CatShooter is talking about on a 300 RUM with a match chamber. The brass was never neck sized only FL every time. I swear.

It has to do with an off the shelf die not resizing the brass enough right at the junction where the web ends and the standard wall of the case begins. The only way to fix it is to have a set of dies matched to the chamber. Which basically is a small base die.

What you said... and what Kevin calls a problem, may not be a problem to everyone.

I do not mind tight cases in my rifles and don't even own a FL sizer for most of then (and I own a lot)

Four of five years ago, I threw our almost 400 pieces of 22-250 Winchester brass that had been fired about 45 times each - neck sized through 5 barrels. The first three barrels, I could get the brass into the replacement barrel - on #4 and #5, I bought a used RCBS FL die, just for the one step to the new barrel, then back to neck sizing. I oiled the cases on the first firing, and I annealed the cases every 4 to 6 firings.

Ed is just mad at me cuz I shot his cats!!!

 

[Barrelnut]

Whatever. Shoulda known I was stepping in it.