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Thread: Busy Weekend - Draft Design of my 9x39 Clone :)

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    Happy Camper hcpookie's Avatar
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    Default Busy Weekend - Draft Design of my 9x39 Clone :)

    Closer and closer...

    I used Microsoft Visio to draft this case design. It is now closer to being finished I believe this is fairly close, probably "close enough" to the original that I'm imitating. You will observe that when I lay my line drawing over the "factory" photo, it almost perfectly matches up


    I have some tool steel rod (o1 I think) that I am going to use to build the actual reamer. I need to compute the size for the chamber. I will make a chamber casting of a 7.62x39 chamber and compare that to the line drawings of 7.62x39 cartridges in all my reloading manuals. I will compare that to the 7.62x39 reload sizing die to verify the difference in sizes.

    Actually now that I hink about it, I may pull out my other country builds - Hungarian, Yugo, Romy, and Chinese, to get an average size between them.

    That SHOULD give me a really close idea of how much larger the chamber needs to be. As discussed on recent threads, I think this will be .003" larger. It would be less if it were a match chamber, but according to the reamer design info I've found on the web, I think .003" is a good number that will provide reliable operation in a semi.


    This diagram is incomplete - I still need to insert the diameters at the neck.


    The more I look at it, I think brass will be tricky. I'm not sure if 7.62x39 can be fireformed and keep that large of a neck. Ditto for PPC brass. I may be able to use Grendel brass because this will be longer than a Grendel.



    I originally set the shoulder at 30 degrees. I was surprised to see that the shoulder angle is still 17 degrees, just like an AK. It certainly LOOKS steeper, I was guessing 25-30 degrees, but the angle tool indicates it is right at 17. MAYBE 20, but I don't have a better picture to work at. I'm still undecided on whether to keep it at 17. Now that I think about it, my 7.62x39 headspace gauges may work if I keep it at 17 but I need to look more closely.


    That big bullet takes up a bunch of room on the powder, huh? I wonder if they use a "compressed" load?









    You saw it here first!
    Gunco Member #10

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    The "original" Boltcutter Rivet Squeezers:
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  2. #2
    No Hope For Me 1biggun's Avatar
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    You saw it here first!

    I dont see anything?? the picture does not come up.

    What are your planes for dies ??? are you going to make 2 reamers one for the chamber and one undersize for the dies? If you do fire fom and neck size 0nly then the brass is going to be tight (not .003 clearance). seems to me you need to make the actual dies and casing first then. then cut another reamer for the actual chamber. that is over size. I would use the case that allows the best bullet seating when choosing between PPC or grendal brass. If the PPC is doable that would be a great as the brass will always be there.

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    Gunco Member bmoore0866's Avatar
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    yeah, no pic, try putting it back on here again, id like to see it.

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    tired of idiots vz58's Avatar
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    more, I want more

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    Happy Camper hcpookie's Avatar
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    oops looks like DynDNS had a problem tonight - try refreshing now
    Gunco Member #10

    http://pookieweb.net


    The "original" Boltcutter Rivet Squeezers:
    http://pookieweb.net/AK/rivet/boltcutters/boltcutter.htm


    Project Pink - the Pink and Blue AK-74:
    http://pookieweb.net/pink/pink.htm

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    No Hope For Me 1biggun's Avatar
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    Do you think the straigther case will work in the curved AK mag??

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    Happy Camper hcpookie's Avatar
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    Quote Originally Posted by 1biggun
    Do you think the straigther case will work in the curved AK mag??
    Nope! Never planned to use factory mags.

    The closest "factory" mag will be a .223 flavored mag. The synthetic Mini-14 mags are the main candidate right now, but that is subject to change.

    This one:

    http://www.copesdist.com/images/Mini...rMagazines.jpg

    or this one:

    http://www.copesdist.com/images/EagleMini1430rnd..jpg

    Now... if neither of those work, I plan to make my own mags with my sheet metal brake. I may just do that anyway. Note the "factory" mags are similar to an AK-74 mag or a FAL mag. Since the FAL style works, I can infer that they don't need the curved mag:


    AK-74 style. Note the divots in the mag look suspiciously close to the magazine well dimples. I strongly suspect they used the same stamping process since it was already there and why reinvent the wheel? They bulge outward, so for the mag design to mimick the "factory" mag, I would use a magazine well dimple (just happen to have one) and dimple the sheet metal, then bend it in my brake. Rhino has enlightened me in the past about curved brakes, so I could make the "mold" out of wood or aluminum and bend the curved end, then the sides. Complicated? Yes. Time consuming? Yes. Impossible? No. I don't have a bead roller. Yet.


    and FAL style. The is the 9A-91 which is basically a VZ-58 on the inside with a 9x39 barrel. Gee, I wonder why I took the time to build a VZ-58 trigger group?

    This would be super-easy to make, just a few bends on the sheet metal brake, and a few spot welds. Then weld on the magazine locking lugs (gee, didn't I do that on my G3 mag conversion?!?!? ) and you're set.

    Gunco Member #10

    http://pookieweb.net


    The "original" Boltcutter Rivet Squeezers:
    http://pookieweb.net/AK/rivet/boltcutters/boltcutter.htm


    Project Pink - the Pink and Blue AK-74:
    http://pookieweb.net/pink/pink.htm

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    Gunco Member bert01's Avatar
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    9x39.jpg

    whats the OAL and the bullet length?

  9. #9
    Happy Camper hcpookie's Avatar
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    That looks cool!
    Quote Originally Posted by bert01

    whats the OAL and the bullet length?
    Umm... classified. Actually I haven't got those yet. Soon...
    Gunco Member #10

    http://pookieweb.net


    The "original" Boltcutter Rivet Squeezers:
    http://pookieweb.net/AK/rivet/boltcutters/boltcutter.htm


    Project Pink - the Pink and Blue AK-74:
    http://pookieweb.net/pink/pink.htm

  10. #10
    Gunco Member bert01's Avatar
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    rim isnt correct i did it in a hurry

    compared to some other stuff

    compare.jpg

    .22 RF, .223, 9x39, .308, 50 BMG

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