Is annealing 7mm STW brass worth it?

Discussion in 'Reloading' started by gamehawker, Apr 20, 2013.

  1. gamehawker

    gamehawker Well-Known Member

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    I've got over 500 pieces of Remington 7mm STW brass last year and been reloading it for my two 7mm STW Senderos. I've been only using 200 pieces of it (saving the other 300 hundred until the current 200 is worn out) and have been getting good groupings after I have reloaded it three times.

    I've heard that 7mm STW brass is usually only good to last for about 5 reloads.

    I've also heard that you annealing brass after about after 5 reloads too.

    Would it be worth it to me to purchase a Benchsource Annealing Machine for my 7mm STW brass or a waste of money because the 7mm STW brass case life expectancy?

    I also have over 100 Winchester 7mm STW nickel plated brass from my Dad. Do you benefit from annealing nickel plated brass?

    Thanks!
     
  2. MudRunner2005

    MudRunner2005 Well-Known Member

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    Always wondered.....Most folks seem to get cracked necks or shoulders, but mine seem to always blow out around the belt and base while the shoulders and necks tend to remain fine. So, I guess anything is possible.


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  3. westcliffe01

    westcliffe01 Well-Known Member

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    "Regular" bottleneck cartridges headspace off the shoulder (firing pin pushes the case forward till it stops), then when fired the case stretches backward until it touches the bolt face. So if your body or FL die tends to knock the shoulder back too much, it will stretch the brass near the base with every firing until the case head finally separates.

    What you showed in the picture looks like a belted Magnum case. Those are supposed to headspace off the belt. But again, if the chamber is too generous for the shoulder position, and your die knocks the shoulder back after every firing, it will only be so many cycles before the case head separates.

    There is something wrong between your chamber dimensions and your die dimension to cause that problem. I don't own any belted magnums nor dies for them, but I think you need to increase the distance to the shoulder on your brass so that it does not need to be stretched with every cycling. It is certainly not the kind of failure mode I want to be having with my brass....

    OK, below is the 8mm Rem Mag which apparently is the parent case.

    If the dimension E (5.59mm) or L1 is off, it will create the problem you are experiencing. Have you ever bought a head space gauge to check ? $30 to save your brass ?

    [​IMG]
     
  4. MudRunner2005

    MudRunner2005 Well-Known Member

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    Those brass had been reloaded like 4-5 times. Most belted mags don't last that long. I think the brass just wore-out.
     
  5. westcliffe01

    westcliffe01 Well-Known Member

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  6. MudRunner2005

    MudRunner2005 Well-Known Member

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    The scary part is, is that all I use are neck-sizer dies for my bolt-actions....

    I think only other option is bad brass, or just work-hardened it too much, and it got brittle... That's the only options I can think of.
     
  7. westcliffe01

    westcliffe01 Well-Known Member

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    Or the distance from bolt face to belt groove in chamber is off 0.006-0.010. That will do it for sure... This type of brass has 2 different failure modes for case head separation. If either the space to the shoulder from the belt, or the space from bolt to belt is off it will cause the same problem. If you neck size only though, then it suggests the primary head space is off. $30 gauge will tell you that. To fix it though (Remington) would require some material removed from the barrel shoulder.

    Just how much does that brass cost ??? For me 6.5x284 Norma was about $1.25 a piece. I sure as heck want to get all the life I can out of expensive (and unobtainable) brass.
     
  8. MudRunner2005

    MudRunner2005 Well-Known Member

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    I'll probably take it to my smith when I get my action for my .280 AI build.
     
  9. gamehawker

    gamehawker Well-Known Member

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    I have to say that "MudRunner2005" HIGHJACKED my thread!!!:rolleyes:

    If you want to talk about your own 7mm STW brass problems, START your own thread!!!

    Now can we get back to MY (the Original Poster of this thread) questions?

    I've heard that 7mm STW brass is usually only good to last for about 5 reloads.

    I've also heard that you annealing brass after about after 5 reloads too.

    Would it be worth it to me to purchase a Benchsource Annealing Machine for my 7mm STW brass or a waste of money because the 7mm STW brass case life expectancy?

    I also have over 100 Winchester 7mm STW nickel plated brass from my Dad. Do you benefit from annealing nickel plated brass?

    Thanks!
     
  10. MudRunner2005

    MudRunner2005 Well-Known Member

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    It wasn't intentional...
     
  11. westcliffe01

    westcliffe01 Well-Known Member

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    The links I posted earlier were for 7mm Mag brass. Very similar to your brass. If the brass fits the chamber well and is not FL sized every time, it should last a good while. Yes, how soon you need to anneal the neck/shoulder depends on how "loose" the neck is in the chamber. The "looser" the sooner you will need to anneal.

    If you get an annealing machine, it will make the process easy. I followed the Youtube "anneal in a baking tin" method and did 500 cartridges in 2 evenings, about an hour each.
    [ame=http://youtu.be/190rC0iTN5M]How I Anneal Brass - YouTube[/ame]

    How frequently you do a batch depends on the rate you shoot. With the above method, you could do it after every 3 firings. Thats what I plan on with my 243 AI shells which are fireformed in the chamber.
     
  12. WapitiBob

    WapitiBob Well-Known Member

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    I have to anneal my STW brass after the 2nd firing or I can't get my sizer back out of the neck without lots of "torque". I'll get one more firing and then the case cracks as shown by mudrunner. My dies don't touch the shoulder either. If you can get factory brass for $.65 probably not worth it. If you buy from an individual at $1.00 it starts to look promising, provided you get enough brass life otherwise.
     
  13. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Bob, I'd graphite(lube) your necks to ease the pull on them- brushing the carbon out with a fresh bronze brush sometimes helps too. I'd also try to find the reason you are loosing brass to seperation.
    I can't get rem stw brass easier than anyone else right now so I may be looking at annealing brass if it work hardens; the shop I bought out of remmy 7stw brass got in nosler at $70 per 25 casings. I'll make brass from something else first.....
     
  14. WapitiBob

    WapitiBob Well-Known Member

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    I never thought of bronze. I use the plastic brush but it doesn't do anything. I'll try the graphite.
    Not sure what's causing the separation, it's always happened with this setup. I do know the neck is the only thing that moves. My shoulders don't move even after a 3rd firing but the neck grows over .005". I measure both neck and shoulder from the base.