Question Regarding Redding Bullet Seating w/o Crimp

Discussion in 'Reloading' started by Brown Dog, Mar 21, 2007.

  1. Brown Dog

    Brown Dog Writers Guild

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    I've only ever reloaded 308 and 300WM; for both calibres I have only ever used Redding die sets. This 'problem' has bugged me for years. Grateful for any views / answers:

    When it comes to bullet seating, I have always followed the requirement stated in the instructions regarding the need to back the seating die away from metal to metal contact with the shellholder in order not to crimp the case.

    However, it has always struck me that hard shellholder-to-die contact would be a far more consistent means of stopping the press's upward movement of the shellholder.

    ...without shellholder-to-die contact the upward shellholder movement is only stopped by the press reaching its mechanical limit of movement. Obviously there is minute slack in all presses, and so vigorous hard press strokes produce bullets seated to a different depth to slow soft press strokes.

    ...and thus 'consistency' of press stroke is vital to consistent bullet seating depth.

    ...which requires concentration, slows things down (and is boring!).

    (but obviously there's no problem if you seat with crimp!)

    FINALLY (!) MY QUESTIONS:

    Does, as I suspect, hard shellholder-to-die contact enable consistent bullet seating despite inconsistent press stroke speed/vigour?

    Can the 'crimp' bit be easily polished out of the seating die to enable shellholder to die contact without crimping?

    Is this a problem with all brands of seating die?


    Thanks if you read this far!

    Matt
     
  2. Brown Dog

    Brown Dog Writers Guild

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    btt.

    Not the most exciting question I guess! ...but still interested if anyone has a view.

    Thanks

    Matt
     

  3. wapiti13

    wapiti13 Well-Known Member

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    Not all presses are created equal. Yes, most "regular" dies crimp at the top of the stroke unless you back die off shellholder. Most quality presses are fairly consistent with dies backed off, but why use a regular die? If you are serious about LR relaoding, go to the Redding benchrest dies (or Forester if you want cheaper) and eliminate the crimp function within the die. Better quality seating dies that can be bought separately. Good luck. /ubbthreads/images/graemlins/cool.gif
     
  4. Brown Dog

    Brown Dog Writers Guild

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    wapiti13,

    Many thanks for your reply!

    On the redding and forster benchrest dies, does the shellholder contact the base of the die ?

    (I get all the accuracy I'm capable of from my standard dies, in 308 I have one standard load that never changes (it'll give me < 0.3MOA in a 100 metre pipe range) but I'm bored of concentrating on consistent press stroke! ....I'm wondering if I could simply get the crimp ring polished out of my standard die?)
     
  5. älg

    älg Well-Known Member

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    Cant tell you about polishing your current dies; but the Redding and Forster Comp. seating dies have a piece imitating the chamber that slides inside the die as the case contacts it.-so it´s not the die that contacts the shellholder but this piece.Hope this helps.
     
  6. Brown Dog

    Brown Dog Writers Guild

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    [ QUOTE ]
    the Redding and Forster Comp. seating dies have a piece imitating the chamber that slides inside the die as the case contacts it.-so it´s not the die that contacts the shellholder but this piece.Hope this helps.

    [/ QUOTE ]

    Thanks älg,

    Does the sliding piece contact the shellholder hard enough that it stops the upward movement of the shellholder

    .....or are you still reliant on the press reaching its mechanical limit of movement?
     
  7. älg

    älg Well-Known Member

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    No it is not hard enough.-it relies on a spring that is on top of the die, and the idea ( as far as I know-I just started using these dies)is that the case is driven inside the sliding piece in order to be centered when the bullet is sat- .

    However you got me thinking and after writing the paragraph on top I´ve run to the press and set the redding die.- If the die is screwed down enough, you can sit the bullets without needing the press ram to reach it´s limit in the press ( I mean you do not need to pull the handle to the maximum)...The sliding piece stops when the shellholder touches the die.

    But you still need the shellholder to touch the die; you are just avoiding the so called "cam" movement of the press when the handle is at full stroke.

    Maybe you could change the spring but you would get very inconsistent results when sitting bullets unless you were able to apply exactly the same force evry time.
     
  8. älg

    älg Well-Known Member

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    Or you can leve the die high enough so that the shellholder does not touch the die at full stroke; but you will suffer the dreaded "cam" of the ram.
     
  9. Brown Dog

    Brown Dog Writers Guild

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    [ QUOTE ]

    If the die is screwed down enough, you can sit the bullets without needing the press ram to reach it´s limit in the press ( I mean you do not need to pull the handle to the maximum)...The sliding piece stops when the shellholder touches the die.

    But you still need the shellholder to touch the die; you are just avoiding the so called "cam" movement of the press when the handle is at full stroke.


    [/ QUOTE ]

    älg,

    Thanks, that sounds exactly what (I think!) I want.

    To my mind, shellholder-to-die contact must surely be a more consistent 'stop' than the press's mechanical limit of movement (?).
     
  10. wapiti13

    wapiti13 Well-Known Member

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    Bottom line is that the benchrest dies don't rely on the position of the stroke per se. Shell is held in the sliding "seating chamber" and can't go further than wanted since the forward motion is stopped. The seating stem or micrometer setting then controls final seating. Also, these dies tend to use the ogive better to contol seating depth and is much more consistent. /ubbthreads/images/graemlins/smile.gif
     
  11. Brown Dog

    Brown Dog Writers Guild

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    Thanks!
     
  12. victor

    victor Well-Known Member

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    Greetings Brown Dog,

    I truly beleive your worries are unfounded.

    I have a RCBS Rock Chukar Press. It has a cam like stroke. If you pull the handle up, the ram goes up. If you go past the ram full up position, the ram come down a little (put a line with marker on the ram shaft at full up position and see if it goes down a little when the handle goes past center).

    My point is that the presses stroke has the same effect as the cam in your vehicle motor that lifts up your valves.

    Now the valves in your vehicle motor have springs that exert pressure on your valves which keep the valve stem in constant contact with the cam.

    In your loading press the "spring force" is actually the resistance of your brass being deformed as the bullet is pressed in. You would have to be pulling your handle faster then a mortal man would be cabable of to create enough speed induced momentum to force that piece of brass to leave the surface of your rams base.

    So in conclusion, with the resistance of bullet insertion, your brass base will never be able to jump up and away from your rams base.

    As a matter of fact, if you did make your press hit a solid metal to metal stop, you will, more than likely only cause premature wear on the bearing surfaces of your press.

    Regards,
    Vic
     
  13. britz

    britz Well-Known Member

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    I sent this infoe to Brown dog already, and I finally figured out how to post pictures so I will send it to the general public.

    In order to make a metal on metal stop for each seating w/out crimping I used a regular washer that fit fairly snug around the cartidge that I was seating for. I filed the washer on both sides to make it true to w/in 0.001" on both sides and I drilled two holes in it at the outer edges to put a thin wire trough to tie it up by the seater die (so I wouldn't have to take it on and off for each cartidge). I used simple paperclips to hold it w/ a rubber band (very crude, but it seems to work). I just finished loading 35 rds for testing and I measured each one to the ogive. It seemed to take about 5 seatings to get everything "settled in" because the first five bullets were seated about 0.002" longer than the rest. After the first five, they all stayed w/in 0.001", so I ran the first five through again. I know, it is very crude, but I was looking for an inexpensive way to make my loads a little bit better.
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