Full auto to semi auto conversion?

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  • M1 carbine dad

    Marksman
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    Aug 16, 2010
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    Danville
    Quick Question:
    In general, how are full auto firearms made into semi auto? is it just a new trigger group? Or are there other things based on the particular firearm?
     

    Herr Vogel

    Marksman
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    0   0   0
    Jun 10, 2018
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    Rossburg
    Legally? If I recall correctly, it's 'once a full auto, always a full auto'.
    So let's say you wanted to take Grandpa's Korean War bringback Kalash and (legally) convert it to semi auto. You would have to destroy the receiver by flame cutting it into three pieces, with each cut removing at least a 1/4" strip of material and going through critical mechanical surfaces. Then you would weld the receiver back together, as well as modifying it to ensure that it cannot receive a full auto trigger group, bolt carrier, et al. Or just buy a semi-auto receiver and build on that.

    But I am not a lawyer, so take that with a grain of salt.
     

    Leadeye

    Grandmaster
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    Jan 19, 2009
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    Like VUPD said, it's very dependent on the action. Back in the 70's some early SA copies of FA open bolt guns where the trigger group was just rearranged to make the gun fire SA were made. These didn't set well with the ATF and soon things required further modification as it was ruled too easy to convert the new SA group to a FA status.
     

    Tactically Fat

    Grandmaster
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    22   0   0
    Oct 8, 2014
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    Indiana
    Example: An AR lower receiver that has a registered lightning link inside - remove the lightning link. Because the LL "is" the machine gun / registered part in this scenario.

    Full-auto HK sear pack? Just remove that sear pack and put in a regular sear pack.

    Other guns - the cut and weld and document process seems to be the only way for us mere mortals to do it.

    If a gun still owned by a governmental agency - it may not need the extensive cut and weld jobs. My brother-in-law's police department has 1 M-14 rifle as a part of some kind of Federal lend-lease program. It's a Vietnam-era rifle that was originally a FA gun, but is now converted to semi-auto somehow (i'm completely ignorant on the process of achieving this in an M-14). But I know it hasn't been cut/welded.
     

    Cree

    Sharpshooter
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    1   0   0
    Dec 28, 2016
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    Lafayette
    What kind of gun is it? The reason I ask, similar to a response above, it could likely wreck the value. If it is a pre'86 and can be legally owned, I would either keep it intact or sell it and re-invest the money into something closer to what you might want. Andy
     

    Cameramonkey

    www.thechosen.tv
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    35   0   0
    May 12, 2013
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    Camby area
    Example: An AR lower receiver that has a registered lightning link inside - remove the lightning link. Because the LL "is" the machine gun / registered part in this scenario.

    Full-auto HK sear pack? Just remove that sear pack and put in a regular sear pack.

    Other guns - the cut and weld and document process seems to be the only way for us mere mortals to do it.

    If a gun still owned by a governmental agency - it may not need the extensive cut and weld jobs. My brother-in-law's police department has 1 M-14 rifle as a part of some kind of Federal lend-lease program. It's a Vietnam-era rifle that was originally a FA gun, but is now converted to semi-auto somehow (i'm completely ignorant on the process of achieving this in an M-14). But I know it hasn't been cut/welded.

    Its probably had a SA sear installed and the FA hardware removed. It still likely has the 3rd hole and cuts internally for the FA sear hardware. (speculation, I know enough to be dangerous) Theoretically if those could be filled it might work, but knowing how .gov works even fully neutralizing those voids isnt enough.
     

    Floivanus

    Sharpshooter
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    2   0   0
    Dec 6, 2016
    612
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    La crosse
    Legally? If I recall correctly, it's 'once a full auto, always a full auto'.
    So let's say you wanted to take Grandpa's Korean War bringback Kalash and (legally) convert it to semi auto. You would have to destroy the receiver by flame cutting it into three pieces, with each cut removing at least a 1/4" strip of material and going through critical mechanical surfaces. Then you would weld the receiver back together, as well as modifying it to ensure that it cannot receive a full auto trigger group, bolt carrier, et al. Or just buy a semi-auto receiver and build on that.

    But I am not a lawyer, so take that with a grain of salt.
    The torch cut requirement is for manufacturers and importers, citizens are allowed to make a single saw cut thru the receiver
     

    Fargo

    Grandmaster
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    13   0   0
    Mar 11, 2009
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    In a state of acute Pork-i-docis
    Example: An AR lower receiver that has a registered lightning link inside - remove the lightning link. Because the LL "is" the machine gun / registered part in this scenario.

    Full-auto HK sear pack? Just remove that sear pack and put in a regular sear pack.

    Other guns - the cut and weld and document process seems to be the only way for us mere mortals to do it.

    If a gun still owned by a governmental agency - it may not need the extensive cut and weld jobs. My brother-in-law's police department has 1 M-14 rifle as a part of some kind of Federal lend-lease program. It's a Vietnam-era rifle that was originally a FA gun, but is now converted to semi-auto somehow (i'm completely ignorant on the process of achieving this in an M-14). But I know it hasn't been cut/welded.
    Most of those guns simply have the selector switch removed and replaced with a little device which locks it into SA. It was done by the army way back when they came to the conclusion that FA .308 was not suited to the platform.

    They are still legally machineguns and all it takes is a selector switch to re enable FA. They are stamped to whatever department has them.
     

    Floivanus

    Sharpshooter
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    2   0   0
    Dec 6, 2016
    612
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    La crosse
    Why do you think that?
    Big in the AK community and many, many AKs were imported with a single saw cut...

    Since that point in time no INDIVIDUAL has asked BATFE and gotten a response back about demil procedures. The new importer procedures actually want them to make torch cuts thru the trunnions, making VERY important parts scrap metal
     

    Kirk Freeman

    Grandmaster
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    8   0   0
    Mar 9, 2008
    47,969
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    Lafayette, Indiana
    Quick Question:
    In general, how are full auto firearms made into semi auto? is it just a new trigger group? Or are there other things based on the particular firearm?

    M1, just want to make sure I understand, you are just asking by what criteria does ATF accept a design as Title I, right?

    You aren't looking to convert anything, just an intellectual question, right?
     

    User 0

    Shooter
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    0   0   0
    Jul 28, 2018
    7
    1
    Walnut Creek
    Obviously it's going to be different based on the platform. An MG-42 isn't going to have the same steps as an Ar-15. When building an MG-42/53/3 from a kit you will need to cut out the front of the trigger assembly slot to fit the larger trigger group, get a semi only bolt group, and weld in a block that will not allow a full-auto bolt group to be installed.
     
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