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    Senior Member amadeus76's Avatar
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    Minimum Case Length?

    So question... Is there a issue if the case length is below the recommended ‘trim-to length’? My Speer manual recommends 2.230” for 8mm Mauser and Hornady recommends 2.240”. However, some are coming out of the resizing die between 2.221”-2.223”. Then I checked some cases that haven’t been resized and they’re sitting around 2.222” as well. Should I be concerned about loading these? What is the minimum case length I can safely use, reload, and shoot?

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    Contributing Member Jonzie's Avatar
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    Hope this helps, I shoot 30-06 and my Lyman manual says to trim to 2.484 and I have loaded and shot some rounds that are at 2.471 with no problems.
    I do not crimp my loads and am shooting out of my 1903s.

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    Advisory Panel browningautorifle's Avatar
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    No problem, your cases will stretch and then you can trim them down to make everyone happy. The case neck will flow forward with firing.
    Regards, Jim

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    Really Senior Member Sunray's Avatar
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    Depends on who you ask. SAAMI, Stateside, has one standard. While CIP in Europe has another. Both of which are usually far shorter than any Trim-to.
    SAAMI Max case length is 2.240" -.020". That's 2.220" being minimum. 10 thou shorter than the 2.230" Trim-to given by Hodgdon. So anything between 2.220" and 2.230", but shorter than 2.240" is good. It's best to have all the same length to start.
    Trimming isn't something you do every time. Checking case lengths is done every time though. Lock your Vernier calipres at 2.240" and use 'em as a case length gauge.
    And don't forget to chamfer and deburr.
    Spelling and Grammar count!

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    Contributing Member Ovidio's Avatar
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    I never had any troble trimming with the Lee trimmer. That size seems to be ok on all my Mausers, from the Gew. 98 to the K98kicon and the Persian. Never really checked the length with that trimmer, but it works just fine.
    34a cp., btg. Susa, 3^ rgt. Alpini

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    Member OldManMontgomery's Avatar
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    It is possible to have one of two or three problems with short cases. None of which will cause a catastrophic failure.

    A short neck gives one less contact of bullet with neck, to hold the bullet in place. However, the case would have to be on the order of .250 inches short to have serious problems seating the bullet properly.

    A short neck exposes the inside of the chamber (neck) to the rather hot burning gases. Probably not a big deal with cases several thousandths short. One doesn't want to erode the last quarter inch of chamber, either.

    The biggest problem is that of seating the bullet deeper and 'crowding' the burning chamber (inside the cartridge case). Seating the bullet too deep will cause initial pressures to rise quickly. So pay attention to the over all length of the loaded cartridge and do not worry about the bullet protruding from the case a bit more than usual.

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    Senior Member Daan Kemp's Avatar
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    Measure new factory ammunition to see how case length can differ without you ever knowing or realising it.

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    Advisory Panel Patrick Chadwick's Avatar
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    Quote Originally Posted by amadeus76 View Post
    So question... Is there a issue if the case length is below the recommended ‘trim-to length’? My Speer manual recommends 2.230” for 8mm Mauser and Hornady recommends 2.240”. However, some are coming out of the resizing die between 2.221”-2.223”. Then I checked some cases that haven’t been resized and they’re sitting around 2.222” as well. Should I be concerned about loading these? What is the minimum case length I can safely use, reload, and shoot?
    Just my 5c, without any kind of guarantee! Check the data yourself!

    No, there is no problem.

    The MINIMUM chamber length (CIP) is 57.3mm = 2.256"
    The MAXIMUM case length (CIP) is 57.0mm = 2.244"
    Hence the Hornady and Speer recommendations, as the reloaders measurements also have a tolerance! Those trim-to values are safety MAXIMA.

    Excessive case length is DANGEROUS, as a jammed case mouth will cause an unpredictable and serious increase of pressure. Hence the 0.012" CIP minimum clearance.
    However, as all manufacturing processes have tolerances, it is no surprise that new case are shorter than the above maximum, so that all cases that come on the market are within the limits. Your cases are probably OK, and do not seem to have stretched. They do not normally become shorter with use, but you must check for stretching!
    I would not trim but bin cases that go over the maximum length, as this indicates that the brass has become severly stretched and is heading for a neck separation.

    A case with a shorter neck will hardly be noticeable, down to the point where the bullet is not properly held in the neck and there is a free-flight before it engages in the lands. Usually accompanied by sooting of the neck because of poor obturation and obviously degraded accuracy. And even then I do not see that it is dangerous, as the early release of the bullet from the neck acts to reduce peak pressure. I have even been next to someone on the range who accidentally fired 308 cartridges in a 30-06. That was effectively using a case with a neck that is several millimetres too short! The case came out of the chamber pretty well neckless!

    Think, for example, of using .38 Special in a gun chambered for .357 Magnum. Or .22 short in .22 long. Did you ever heard of safety worries?

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    Senior Member bob q's Avatar
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    After a lot of pressure testing with strain gauges, it disproves the old myth of a deeper seated bullet in a bottle neck rifle case raising pressures . The powder does not start to fully burn and produce high pressures until the bullet hits the lands of the barrel . So unless there is something really abnormal with the chamber a short seated bullet makes no more pressure . And yes you can fire 308 in a 30/06 with no problem even though there is a massive head space problem . Just funny cases when you are done .


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