300 WM. Crimp or not to crimp?

Discussion in 'Reloading' started by RICHARD PERRETT, Nov 29, 2019.


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  1. RICHARD PERRETT

    RICHARD PERRETT Active Member

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    Just started reloading for a 300 wm. First thing I noticed was was the short neck for caliber. All my previous reloading has been for 308 0r 30-06 based cartage cases. My question is will I have sufficient neck tension without putting a crimp on the bullet? Just developing loads so starting with IMR 4831 and H4350. 208 eld M, Sig cases,Win large mag primers. These powders are what I have on hand. i'm not worried about extreme velocity as 800 to 900 yards is the farthest I
    anticipating shooting. Thanks for any help. If you don't reload I do not what to hear your theories.
     
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  2. ShtrRdy

    ShtrRdy Well-Known Member

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    If it's for a bolt gun don't worry about crimping.
     
  3. MagnumManiac

    MagnumManiac Well-Known Member

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    Crimping does not enhance neck tension, it actually reduces neck tension. Also, it’s not a good idea using a crimp on a bullet without a cannelure anyway.
    The only cartridges I crimp are for tube fed guns and DG cartridges. I don’t even crimp my 375 Weatherby.

    Cheers.
     
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  4. surgeon260

    surgeon260 Well-Known Member

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    I reload six different centerfire cartridges up to 338 Lapua. I have never crimped any of them and never will.
     
  5. sturner

    sturner Well-Known Member

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    The only rifle I crimp is my 45-70
     
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  6. RICHARD PERRETT

    RICHARD PERRETT Active Member

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    Thx MM for the tip
     
  7. RICHARD PERRETT

    RICHARD PERRETT Active Member

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    thx 260
     
  8. rsmithsr

    rsmithsr Well-Known Member

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    crimp can work on ammo the is limited in length by magazine, it can help the start pressure.
    BUT
    it is the last thing to try, not normal at all.
    none of my 300 win mags get a crimp.
     
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  9. RevJim

    RevJim Well-Known Member

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    I crimp everything with a LEE Factory Crimp Die now. I believe it helps with "bullet pull consistency", therefore accuracy. Its not hurting anything I can see!
     
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  10. rsmithsr

    rsmithsr Well-Known Member

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    depends on your version of ACCURACY.
    if you are under 1/4 moa, if not...stop.
     
  11. sturner

    sturner Well-Known Member

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    If it ain’t knurled don’t crimp
    Bad on dies
     
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  12. Mram10us

    Mram10us Well-Known Member LRH Team Member

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    Ok, I’ll bite. Reduce neck tension??? What am I misunderstanding here?
     
  13. aushunter1

    aushunter1 Well-Known Member

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    How far into the case mouth is your end seating depth, this is the question??

    If you have the projectile seated towards the land so far you have minimal grip then yes it may help.
    But I am talking 25% or less the length of the case mouth.

    I have never needed to crimp, even when seating a .22-250 just a few millimetres into the case mouth.

    With correct neck tension even a few mm is enough but yes it would depend on the amount of recoil the rifle produces.

    I know from other things I have read where people are loading for say 30-30's that many people that played with crimping found it did improve accuracy.

    I dare say this just changed the pressure level to influence the accuracy node, but then again they have to crimp due to the tube magazine where as you don't need to.
     
  14. catamountsierra

    catamountsierra Well-Known Member

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    The only crimp I have ever used is the Lee Factory Crimp die, and have found that it has helped accuracy in several factory guns. I plan to use it for fireforming loads for my 284 and 223AI, but once I start load development I test with and without the crimp to see which gives me the better accuracy. Also, use a very light crimp with the Lee die. A crimp seems to help by evening out pressure needed to start the bullet, and it doesn't take much to do that. I will say, that die can really crimp down hard, even with bullets that lack a cannelure, but heavy crimps have always degraded accuracy.
     
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