Cast bullets in a mini30

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  • guzma393

    Active Member
    Jan 15, 2020
    736
    Severn, MD
    This has been a long going project of myns to accurize an early serial # mini 30 that shot minute of berm with factory steel cased ammo and minute of paper at best with the brass stuff (100 yards). Some early serial mini 30s are notorious for having barrels cut to .308" rather than .310". On top of this the barrel is susceptable to barrel whip with full power loads. I figured reduced cast loads can alleviate these issues.

    I had good luck with running reduced load casts to address these shortcomings. My current load is a lee .311" sized/160/2R gas checked, powder coated cast pushing at ~1600 fps.

    During that time, id only had 5 round mags to work with. I recently acquired some 20 rounders and noticed right out the bat that the front support tabs are colliding with the ogive profile of the casts preventing the rounds from seating all the way up the feed lip of the magazine.

    Rather than call it quits and try and work up an fmj reload, I decided to take a gamble and grind down the tabs to see if it will feed properly. Tested it out at the range and it fed great, but only tested out about 40 rounds. I tried some factory ammo and they seem to feed just fine even with the tabs grinded down.

    Question to all you mechanical savvy/ gunsmiths out there; would grinding down these tabs pose a risk of premature wear or am I just overthinking it? At 40 bucks a mag, I only plan on doing this to 3 of them as range mags and keep the rest loaded up with factory ammo (I got a Ruger American bolt action x39 that takes the same mags and that runs anything for those). Pics below for reference showing unmodified mag working well with factory ammo vs. modified mag with cast reloads, plus a group at 100 yards (pretty happy with this, considering it wasn't hitting paper with steel cased factory ammo) Any input is appreciated, thanks

    c87bb2786b66ebad9278e071afdc498e.jpg
    95b40f1a0fd4807a641dfad51d9099ea.jpg
    4a046ff2a5830c1ce1bcb43e0be4e737.jpg


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    GuitarmanNick

    Ultimate Member
    Jan 9, 2017
    2,221
    Laurel
    Recently started using cast to develop loads for an SKS and M-44. On both, I found that reducing the OAL was necessary. Perhaps shortening your hand loads would cure the feeding issue without modifying your magazines.
     

    guzma393

    Active Member
    Jan 15, 2020
    736
    Severn, MD
    Recently started using cast to develop loads for an SKS and M-44. On both, I found that reducing the OAL was necessary. Perhaps shortening your hand loads would cure the feeding issue without modifying your magazines.
    Oddly enough, the 5 rounder front tabs do not interfere with the cast reloads. Probably because the 20 rounders are curved rather than straight, affecting the clearance needed from feeding the rounds at an angle.

    I'll try experimenting with shortening the OAL if it is not too drastic. Looking at it closer in comparison with the factory spire/spritzer point ammo, it seems like the OAL has to be reduce drastically to allow enough clearance.

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    Melnic

    Ultimate Member
    MDS Supporter
    Dec 27, 2012
    15,282
    HoCo
    So, the heavier but slower bullet in the Mini 30 cycled OK?
    Not fully off topic but
    I had followed you on reloading the 7.62x39 round before, I don't recall if you ran it on an SKS yet?
     

    guzma393

    Active Member
    Jan 15, 2020
    736
    Severn, MD
    So, the heavier but slower bullet in the Mini 30 cycled OK?
    Not fully off topic but
    I had followed you on reloading the 7.62x39 round before, I don't recall if you ran it on an SKS yet?
    It cycled fine out of the mini 30 using 18.5 grains shooters world blackout, which is comparable to 1680. I got it to cycle with 17 grains where the shells would fall a few feet away from me, but I didn't like the groups it was producing. I have yet tried it on a SKS as I currently do not have one in my possession.

    My father has a Norinco SKS and a zastava mpap Sporter I can borrow and try the casts in, but that's a project in the near future.

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    GuitarmanNick

    Ultimate Member
    Jan 9, 2017
    2,221
    Laurel
    Oddly enough, the 5 rounder front tabs do not interfere with the cast reloads. Probably because the 20 rounders are curved rather than straight, affecting the clearance needed from feeding the rounds at an angle.

    I'll try experimenting with shortening the OAL if it is not too drastic. Looking at it closer in comparison with the factory spire/spritzer point ammo, it seems like the OAL has to be reduce drastically to allow enough clearance.

    Sent from my Moto G (5) Plus using Tapatalk

    Most of the cast load information that I see in Lymans 49th uses a considerably shorter OAL than with FMJ bullets regardless of caliber. That is why shorter OAL is usually listed when using JHPs compared to FMJs, too.

    Ogive shape directly impacts feeding.
     

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