Neck sizing question...

Discussion in 'Reloading' started by The Oregonian, Jul 17, 2014.

  1. The Oregonian

    The Oregonian Well-Known Member

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    My fired brass is .310 and needs to be resized to .303 or .304....is that ok to do in one step (Redding bushing neck sizing die), or do I need to hit it thru another size, maybe .306 or .307 first?

    This is for Nosler brass for 270 win.
     
  2. MagnumManiac

    MagnumManiac Well-Known Member

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    Yep.:D
    gun)
     

  3. The Oregonian

    The Oregonian Well-Known Member

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    Can you clarify? Yep, it is ok to do it in one step, or yep, I need to hit it thru another bushing to do it in two steps?

    Thx.
     
  4. Gene

    Gene Well-Known Member

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    Squeezing the neck down .006 or more in one pass might work, but it puts added stress on the brass. Better to go down .002 - .003" at a tim4e.
     
  5. Mikecr

    Mikecr Well-Known Member

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    Gene's right that excess sizing is bad for the necks, but then you might not have a choice.
    Doing it in one step is really challenging to necks. Eventually they're not going to take it anymore.
    ~5thou is about as much as bushings are predictable with.
    It can be done in one step but the sizing will be more than stamped on the bushing because you end up rolling brass inward instead of sizing inward(due to excess angles).
    So it will be either trial & error to nail it, or 2-stage sizing.

    If you're stuck with this situation and single stage sizing, you should look into an annealing machine.
     
  6. BountyHunter

    BountyHunter Writers Guild

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    Interesting question is why the need to go to .304 in the first place.

    sounds like you have overly thin neck turned brass and are trying to compensate for it.

    Have you neck turned your brass down to .0125-.013 or so?

    Most factory brass is in the .014-.015 range or even thicker, which loaded would put the round at approx .307 and if the fired is .310 your chamber neck is probably .310-.311 range.

    With those wide variances you are going to work harden and split the necks.
     
  7. The Oregonian

    The Oregonian Well-Known Member

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    New to reloading here...got my equipment and just digging in for the first time. I have an off the shelf A-bolt stainless stalker in 270 win. I am not turning necks yet - i am playing with it with a few cases that I won't use, but I think I need to get the basics down before I throw more variables (and more room for error) into the mix.

    I have a 150 or so Nosler once fired cases (from factory ammo) and also bought 50 new brass so I can measure and compare if needed.

    On the Nosler reloading data they show a loaded cartridge having a neck diameter of .308, which allows for .0155 neck thickness.

    Measuring loaded factory Nosler ammo has diameter or .305 which would allow for neck thickness of .014...Most of my cases have a neck thickness of between .014 to .015 (both once fired and new a Nosler brass).

    Based on that, I ordered .303 and .304, as well as .305, .306 and .307 to do a two step and have more flexibility on exact sizing. I arrived at that by taking .305 - .277 to get to .028, which has neck thickness of .014, and subtracted .001 and .002 to get .303 and .304.

    Anything wrong with my approach?

    Thx

    Tom
     
  8. Timber338

    Timber338 Well-Known Member

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    Looks to me like you are right on track figuring out which bushing to use.

    In a lighter hunting rifle like an A-bolt, I would go with the .303" bushing for .002" of interference to get a better grip on the bullets in the magazine during recoil. Or does your rifle have the magazine that supports the cartridge on the shoulder? I've seen some of the browings have those. If that's the case then you could use .001".
     
  9. The Oregonian

    The Oregonian Well-Known Member

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    The .304 and .303 got here today while the .305, .306, and .307 get here in a few days. Just for grins, I went from .310 of the fired brass to .303 to see what would happen.

    The runout on the concentricity gauge was .001 or so on the necks prior to reducing them by .007. Once they were sized down that far the runout went to .003 give or take. Will play with a few combinations of sizes during the two steps to see what gives the least runout and report back.
     
  10. AZShooter

    AZShooter Well-Known Member

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    It would appear that you are doing a good job in working with what you have.

    Some thoughts:

    You said you have measured neck wall thicknesses and they ranged from .014" to .015"? If you use the same bushing you will be varying the neck tension. It could cause larger groups at longer distances.

    In addition to this the chamber of your rifle appears to have a generous neck clearance because you have to reduce the neck diameter of the fired brass down to .006" or .007"

    IMO bushing dies work best with a combination of neck turned brass and a tighter chamber neck. Most custom reamers are spec'ed out with tighter neck dimensions so there is minimal sizing of brass for longer life.


    There is a reason why the factory chamber neck is a bit on the loose side. It will allow for a variety of brands of brass with different wall thicknesses to be fired without the thickest ones having bullet release issues.

    The traditional FL sizer with a sizer ball is used for basic handloading for the same reason. It will take any manufactured brass and size it down then open up the neck for the proper bullet tension. The typical RCBS die is around .003" neck tension .

    If you find you have issues with your accuracy I suggest you buy one of the FL die dies that uses a sizer ball and give it a try.

    One more thing. If you decide to turn your necks so you will end up with consistent neck tension the brass will have a shortened life, unless you anneal often. Why? The brass will be over worked through expansion during firing in the "sloppy chamber neck" then sized enough to hold a bullet.

    As you can see there are two different approaches to handloading. IMO the bushing die approach is best used with a "tuned" package of specified chamber neck dimensions in combination with turned necks, while FL sizer dies with a ball are used with factory chambers and any brass available.

    It took me many years to get this all sorted out. I split my share of necks because I turned them and had factory chambers. Also chased my tail with bullet jump vs magazine lengths till I realized I would never ever use a factory chamber again nor would I use any old reamer. I spec out my reamers. It is just a higher level of performance and it costs far more but the rewards are greater too. Hope this wasn't too much...just trying to help you get a grasp of this fascinating pursuit called handloading.
     
  11. MagnumManiac

    MagnumManiac Well-Known Member

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    My take on this is, seeing as though you have a generous chamber neck, no matter what you do, either sizing or firing your brass is going to 'work' it excessively. This is why I answered "Yep" to your question. You can try to eliminate runout, but again with a standard rifle and chamber you're probably just wasting your time.
    Find an accurate load and seating depth and don't worry about the 'benchrest' techniques, they rarely prove to make a difference in generous chambers anyway.
    I don't want to burst your bubble in anyway, just don't want you to waste barrel life chasing your tail endlessly, just shoot and enjoy your rifle.

    Cheers.
    gun)
     
  12. The Oregonian

    The Oregonian Well-Known Member

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    Many thanks...I have a custom on the way - hopefully in a month or so it is finished up. It is a 30-06 being done by Darrell Holland. That is where I think hand loading will come into play much more squarely. I can't wait to get it and start to load for it.

    I am trying things out until that arrives by playing with my 270...good suggestion on annealing. I will look into that.

    I may keep the 270 as is for a while, but am toying with getting it trued, barreled, new stock, etc and turned into a 280AI. Will just have to see.
     
  13. The Oregonian

    The Oregonian Well-Known Member

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    The other bushings arrived and I went thru a 3 step process last night. from .310 to .307 to .305 to .303. Maybe that is overkill.

    Most stayed fairly concentric (within .001) but every 5th or so case had .002 or .003. I tried going partway on the press then rotating, and also tried going all the way, then rotating, then press thru again. Didn't seem to change the results.

    I have 140 once fired (from factory ammo) Nosler brass...I will likely pull out a handful and try neck turning on those. These will be the first time neck turning so I will start with a handful and check the results before doing a larger number.