Lapua does not recommend re-annealing?

[TC260]

Where did this quote come from...obviously NOT written by anybody that understands metal.

Yes it's written in layman's terms so the language isn't especially precise but what specifically is so far off the mark?

 

[JFrank]

Yes it's written in layman's terms so the language isn't especially precise but what specifically is so far off the mark?

My Girl RW will be with you shortly

 

[AckleymanII]

The air put into tires using a standard air compressor is about 78% Nitrogen and 21% oxygen. That same concentration goes into your lungs.
We had a phosgene generator in one of the units I worked in and when we changed out the carbon bed, It would take about 3 days using heated nitrogen to purge all of the oxygen out.
The tire guys have a racket going.

change the mix to 100% helium and you will get 10 more miles per gallon!

 

[riflewoman]

Since they talk about the results of case hardening and the "Cumulative" effect, I still would like to know it they are only talking about annealing an already annealed case the first time it is loaded from NEW Lapua brass, or never again?

"This movement hardens the brass a bit more. Every time this process is repeated, it adds to the hardening. The effect is cumulative, creating more damage over time. The case loses its ductility, or ability to “spring back” to its original dimensions. This can result in cracks and other failures in the brass. Ever break a wire coat hanger by bending it back and forth? Same concept exactly."

I am going to limit myself to the second paragraph...

I am presuming the “movement” is the sizing and expansion of a shoot-reload cycle? It does add to the hardening but the increase is not linear. Up until a split the “damage” is reversible.

Ductility is not the ability to “spring back” to original dimensions. That is ELASTICITY. Super strong and hard tool steels have the same elasticity as cheap hot rolled stock. The tool steel has limited ductility, less than the cheap stuff. Ductility is the ability to be permanently stretched or formed by bending. Malleability is the ability to be cold formed by hammering. Which is why stronger steels need to be hot forged. A coat hanger bent back and forth tends to fail by strain based fatigue but that is an over simplification. It isn’t from cold work as the number of reversals is too low.

I respond like this because terminology matters. The vast majority of readers on these sites have no clue about how metals react. So we get this erroneous stuff and then a search engine finds it. Someone repeats it and then it becomes “gospel” becuz “I Red it on de internet in sum hide sumwere. “.

 

[KevinThomas]

I never had a split neck, I did and do get split shoulders on NEW Lapua brass. Some from factory induced folds and some from improper factory annealing....jim

The split shoulders are a factory defect (which should be caught during final inspection, but will occasionally slip through), and are normally only seen on a few cartridges. Specifically, the 6.5x47L, the 6mmBR and the 6.5x284 cases. The one thing that all of these have in common is a relatively large body diameter in relation to al relatively small neck dimension. While the material should (emphasis on “should”) form smoothly during the necking phase, it occasionally fails to do so, resulting in a small divot at the neck/shoulder juncture. While this is infrequently seen in other calibers as well, it’s very unusual. With the three cartridges I mentioned, it’s an ongoing struggle for every production run. As I said, it’s considered a production defect, and they will readily replace the cases for you if you let them know about it. Believe me, I replaced plenty over the years, and it’s not an issue. Just let them know, and they’ll take care of you.

 

[johara1]

The split shoulders are a factory defect (which should be caught during final inspection, but will occasionally slip through), and are normally only seen on a few cartridges. Specifically, the 6.5x47L, the 6mmBR and the 6.5x284 cases. The one thing that all of these have in common is a relatively large body diameter in relation to al relatively small neck dimension. While the material should (emphasis on “should”) form smoothly during the necking phase, it occasionally fails to do so, resulting in a small divot at the neck/shoulder juncture. While this is infrequently seen in other calibers as well, it’s very unusual. With the three cartridges I mentioned, it’s an ongoing struggle for every production run. As I said, it’s considered a production defect, and they will readily replace the cases for you if you let them know about it. Believe me, I replaced plenty over the years, and it’s not an issue. Just let them know, and they’ll take care of you.

I have been waiting about 7 years...... what good are a 1000 of one lot and 12 of an other....... zip....... jim

 

[johara1]

OMG!!!
I knew there was a reason I never graduated from a neanderthal sling/coat shooter! LOL

Me too, I shoot them over a hundred times, I can't figure how I could set records with brass that was shot that many times and shoot that small..... maybe annealing does work ... LMAO...... jim

 

[TC260]

Fair enough, I understand what you're saying about terminology. If I'm understanding what you're saying, "original dimensions" is the phrase you're disagreeing with and it being associated with plastic instead of elastic deformation. Yeah technically in order to be going all the way back to the case's "original dimensions", which in this case I suppose would be defined as the sized dimension of the case or maybe the neck size if the bullet were pulled (due to some amount of plastic deformation from bullet seating).

I guess I looked at it as, plastically deforming cases through firing/reloading strain hardens the brass thereby reducing ductility. The reduction in ductility effects the amount of spring back. Considering it's just copy for a general audience, it's true enough as it goes even if it doesn't exactly match the definition of elastic deformation. Either way, this isn't the kind of thing I'm gonna lose any sleep over

 

[rr2030]

change the mix to 100% helium and you will get 10 more miles per gallon!

Thats the kind of pure genus I dredge through threads to read !