When a .308 Cartridge is Chambered in a .25-06 Rifle

    When a .308 Cartridge is Chambered in a .25-06 Gun

    In the capital of Scotland, we find Edinburgh Rifles and Sporting Goods, a registered firearms dealer offering a full range of new and used firearms, ammunition, reloading components, optics and accessories. Like any gun dealer they get their share of “customer experiences” and today you’re going to see what can happen if chamber a .308 Win cartridge into .25-06 rifle.  The saying is that you learn from your errors. I prefer to keep learning from doing things right over and over, but accidents happen.

    Below: Top to bottom – blown out .308 Win, .25-06 Remington, .308 Winchester.

    This is a Sauer 202, which seems to be high-quality gun. Read the description below for the details.

    Here is the story from Edinburgh Rifles and Sporting Goods:

    New Cartridge design for 2022! “.25-08”

    Most chambers are designed with deliberate interference for smaller cartridges so they cant accept shorter cartridges with larger diameter bullets in error.
    Occasionally one slips through and mistakes whilst rare, can happen.
    When a .308 cartridge is chambered in a .25-06…..
    Not only will it chamber but the wrong combination of bullet profile will engage the shoulder area of the .25-06 chamber and allow enough resistance for the primer to ignite on firing.
    This has blown the .308 brass case out at the shoulder and neck to the chamber dimensions of the .25-06 up to the shoulder,
    Blown the brass at the web dislodging a section of the case head.
    Blown the primer out flat
    Blown a lug off the bolt head at the extractor claw.
    The bullet has managed to exit the barrel which means it has been sized down from .308 to .25 cal!!!
    Lot of copper fouling…
    The barrel itself looks in perfect order!!
    No bulges, no chamber marks.
    The only give away is the headspace is now large enough to close the bolt on a NoGo gauge.
    The action is the often maligned aluminium version of the Sauer 202
    Magazine well is blown out and distended with visible stress fractures, but the integrity has not been compromised.
    The magazine itself was blown out through the bottom of the action with enough force to separate bullets from brass and embed a single bullet in the bench.
    The GRP foreend was broken off at the barrel tenon as the action expanded sideways.
    When it came in the bolt was stuck solid.
    Required a barrel clamp and some judicious use of a the shop hammer to loosen it.
    This huge pressure developed in this combination of chamber and incorrect cartridge is likely to have produced in excess of 120,000 psi in a cartridge desogned for leas than 60,000
    It is a testament to the quality of the engineering and materials used in the Sauer 202.
    I am not sure some other brands would be quite so resilient.
    Do keep your ammo separate or choose cartridges that are not able to chamber in the wrong rifle….
    Below: This used to be a .308 Win. Continue to scrolling down for more pictures.
    Eric B

    Ex-Arctic Ranger. Competitive practical shooter and hunter with a European focus. Always ready to increase my collection of modern semi-automatics, optics and sound suppressors. TCCC Certified medic.


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