On this annealing bidness

jackie schmidt said:
Pete, the flaw in your analogy is cases are NOT soft as you get closer to the head. There is a very specific heat treat of the entire case upon manufacture, the the neck and shoulder are then annealed to soften that particular area.

The strength is in the web area. Do not disturb this.
Click to expand...

Finally an explanation even Pete will understand.
 
case head

We at Lake City, hit the case head twice with a pocket operation and a heading operation on 7.62. Both operations were a punch and die setup. Quality would check head hardness every shift. If you had soft heads you changed the punch. But it might be a furnace problem. There was always more than one variable. But that's how we ran 7.62 in the ice age I aint got a clue what they do now. Doug
 
Doug Casner said:
We at Lake City, hit the case head twice with a pocket operation and a heading operation on 7.62. Both operations were a punch and die setup. Quality would check head hardness every shift. If you had soft heads you changed the punch. But it might be a furnace problem. There was always more than one variable. But that's how we ran 7.62 in the ice age I aint got a clue what they do now. Doug
Click to expand...

Thank You!

kewl
 
I want elastic not plastic deformation of the case body upon firing. No, or minimal springback, would not be a desirable characteristic of the body of a cartridge IMO....safety aside.
 
Last edited:
Well

referring to the base web area as hard is a relative thing. We are talking about cartridge brass not steel. However Jackie summed it up....the case maker hardens the brass case variably along it length. The "hardest" part is the base area. Just don't mess with it IMO.
 
a learning experience

I remember when Pete blew up a primer seater using primers that the instructions said not to use in that tool. That was a learning experience. Thanks to Pete we now know it is possible.
 
Pete Wass said:
I had the thought the other day that it might not hurt anything to anneal brass most of the way to the case head. My thinking went to new cases; they must be soft when we fire them the first time,eh? So what would be harmed by returning them to where they were to begin with? Any thoughts?

I plan to try one when I get home.

Pete
Click to expand...

The heads are almost always way harder than the neck and shoulders.

That is why they can safely contain 50,000+ PSI range pressures.
 
If

Lee would only tighten up the tolerances and make their primer tool out of decent material that lasts it would be a winner. For me, K&M.
 
lee's very early hand priming tool has a screw in steel shell holder, pot metal body and handle.
they work great i have a stack of them, dedicate one to a rifle and never look back.

the later tray tool had a thin shell holder "roof" and they would pop loose with use. they improved the roof thickness and those work pretty well also. tho the plastic tray and guide are not perfect at all.
i have not used the new current SAFETY design.
i did pay 20 bucks for a sinclair in 308 case head/small primer that i use..not bad for 20 bucks.
glp said:
Lee would only tighten up the tolerances and make their primer tool out of decent material that lasts it would be a winner. For me, K&M.
Click to expand...
 
glp said:
Lee would only tighten up the tolerances and make their primer tool out of decent material that lasts it would be a winner. For me, K&M.
Click to expand...

Greg, I snarf up all the Lee primer seaters I can (round plastic trays). Just scored two NIB on eBay. ;) -Al
 
Thanks, Greg. I make a plastic sleeve and epoxy it into the loading chute...keeps the primers from flipping. Stay warm! :) -Al
 
retired said:
well and the fact that they are a lot THICKER
might have something to do with that.
Click to expand...

The rupture strength of brass climbs significantly as it hardens.
Almost all actions leave at least some gaps around the case head.
This means the case ALONE in those areas MUST be strong enough for the peak chamber pressure.

So a search for 'brass strength vs hardness chart' and plenty of them will come out.
Some are rather precise.

Cartridge brass was developed for it ductility and work hardening.

The ductility allows a small flat disk to be formed into a case using repeated punching in very precise die sets.
Many cases require annealing part way through forming to soften the brass eliminate excessive work hardening.

Cases can easily have extra strength worked into them by extra strikes in the drawing and forming process.
The strength of brass more than doubles from dead soft to about 60% hardness for many grades.

Case head separations are caused by the cartridge being slightly shorter than the headspace in the chamber.
While this allows the round to enter the chamber with less mechanical force, it means the brass is going to expand
in diameter and increase in length between the bolt face and whatever is stopping the forward movement of the case in the chamber.

Bottle necked cases typically rely on the case shoulder stopping on the chamber shoulder.

There are also plenty of cases that rely on the case mouth.
Some like .45 ACP expand enough in diameter enough to more than make up for any length change that might occur.

Thus the reason .45 ACP brass does not require nearly as much routine trimming as bottle necked rifle cases.
The much lower pressure than most CF rifle cartridges helps also.

Having a case fail when chamber pressure is near peak will release a jet of many thousand degree gas into the gun.

Most actions have tried to provide both obstructions to the jet of gas and a place for it to go that is not in the shooters face.
 
just too many fallacies to respond to.
TECHNICALLY 45ACP chambers on the case mouth, in reality
nearly all fire from the extractor/extractor groove.
brickeyee said:
The rupture strength of brass climbs significantly as it hardens.
Almost all actions leave at least some gaps around the case head.
This means the case ALONE in those areas MUST be strong enough for the peak chamber pressure.

So a search for 'brass strength vs hardness chart' and plenty of them will come out.
Some are rather precise.

Cartridge brass was developed for it ductility and work hardening.

The ductility allows a small flat disk to be formed into a case using repeated punching in very precise die sets.
Many cases require annealing part way through forming to soften the brass eliminate excessive work hardening.

Cases can easily have extra strength worked into them by extra strikes in the drawing and forming process.
The strength of brass more than doubles from dead soft to about 60% hardness for many grades.

Case head separations are caused by the cartridge being slightly shorter than the headspace in the chamber.
While this allows the round to enter the chamber with less mechanical force, it means the brass is going to expand
in diameter and increase in length between the bolt face and whatever is stopping the forward movement of the case in the chamber.

Bottle necked cases typically rely on the case shoulder stopping on the chamber shoulder.

There are also plenty of cases that rely on the case mouth.
Some like .45 ACP expand enough in diameter enough to more than make up for any length change that might occur.

Thus the reason .45 ACP brass does not require nearly as much routine trimming as bottle necked rifle cases.
The much lower pressure than most CF rifle cartridges helps also.

Having a case fail when chamber pressure is near peak will release a jet of many thousand degree gas into the gun.

Most actions have tried to provide both obstructions to the jet of gas and a place for it to go that is not in the shooters face.
Click to expand...
 
"opinions?"

"facts?"

"experts?"

I'm old enough now to have spent hundreds of thousands of dollars on "experts". REAL dollars, not innernet credibility dollars......

-engineers
-architects
-designers
-authors
-gunsmiths
-machinists
-testing laboratories
-etc
-etc

The truth is where you find it...... but where you DON'T find it, EVER, is from the hecklers bitching from the sidelines.

"Step up,"
"take a swing" or,
go back to the kitchen...... because this room is one of the best in the world for finding TRUTH amongst the chaff.
 
What ever for?

A new piece of Lapua brass is about $1, roughly the price of 4 bullets, now none of us got a problem shooting 4 shots, why would you not want to keep fresh brass in your loading block?

Why, if you have a piece of brass that you think is "Compromised" not chunk it in the trash. I would hate to know that I traveled 500 miles, spent the money gas and for 2-3 nights in a hotel, paid the entry fee and then shot like crap because I refused to use new good brass...

Or what about if you keep using some old brass and maybe its what is giving you an occasional flier... how much time and components you gonna go through looking for the issue when all it was is your thoughts that brass should last forever or should fit every one of your BR guns because the chambers should be that close to one another?

Just saying that there ought to be better things to spend your resources on than figuring how ways to get old brass to shoot like new...

But if any of you are going to Phoenix next weekend... ignore this and prove me wrong! ;-)
 
You must log in or register to reply here.
Back
Top