+2 gas system?

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  • natdscott

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    Hohn is right. It tears up your stuff less when you are running heavy bullet loads with slow powders.

    The gas port pressure was never intended to be as high as it is with your Vargets and RE-15s, much less something like MR2000.

    Some argue that reducing port size solves it, but thing is, the Venturi Principal isn’t a theory. Reducing the port size might relatively decrease the VOLUME of gas that gets into the tube before the bullet unseals the muzzle, but it will at the same time relatively increase the SPEED of that gas jet. No free lunch.

    It was only intended for fast powders and light 55-60 grain bullets.

    We have changed the barrel configurations significantly to enable stabilization of steel core ammunition, invented longer bullets to shoot well in those tight twist barrels, and then adapted our powder charges and formulations to perform better with the bigger bullets...

    ...but the port location didn’t change, did it?
     
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    natdscott

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    But don’t be doin a +2 on a 20” tube. Same deal as an 18” with rifle gas, only worse: dwell time isn’t always long enough, and you short stroke.

    I would only consider a +2 in a 24” or 26” tube that I intended to run heavy loads in...like Mk 262 or hotter.

    Light loads like NATO 55 ball are asking for trouble.
     

    natdscott

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    Yeah.

    Light bullets = fast powders. Fast powders have a lower gas port pressure. So no need for extended gas.
     

    AmmoManAaron

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    Hohn is right. It tears up your stuff less when you are running heavy bullet loads with slow powders.

    The gas port pressure was never intended to be as high as it is with your Vargets and RE-15s, much less something like MR2000.

    Some argue that reducing port size solves it, but thing is, the Venturi Principal isn’t a theory. Reducing the port size might relatively decrease the VOLUME of gas that gets into the tube before the bullet unseals the muzzle, but it will at the same time relatively increase the SPEED of that gas jet. No free lunch.

    It was only intended for fast powders and light 55-60 grain bullets.

    We have changed the barrel configurations significantly to enable stabilization of steel core ammunition, invented longer bullets to shoot well in those tight twist barrels, and then adapted our powder charges and formulations to perform better with the bigger bullets...

    ...but the port location didn’t change, did it?


    In your opinion, what are the slowest powders that should be used with a 20" barrel and standard rifle length gas system?
     

    natdscott

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    In your opinion, what are the slowest powders that should be used with a 20" barrel and standard rifle length gas system?

    2000MR will push a heavy .22 bullet as fast as it can go from a 5.56x45, and THEN some.

    Caution being that it doesn’t really like light loads, and seems to want to go fast, but the AR ain’t no bolt gun, and this isn’t a .22-250.

    Being, um, “highly energetic”, and a modified Ball, 2000 also has enough space in the casing, even behind a 90, to blow your **** up RIGHT now.

    RE-15 and Varget and such other slow-ish stick powders aren’t as likely to do that very well, because they take up too much space, and you start crunching powder pretty badly. RE-15 is used a good bit over 100% fill by some guys with the 77SMK at mag.

    (not necessarily this guy)

    That being said, I’d much rather use 2000 for a heavy heavy load than I would RE-15, because despite Reloder’s many-lb space on my shelves, it is a spiky powder on the top end, and it will royally chew up primers, casings, and rifles if you try to get high speed.

    2000 is MEANT for that.

    But not for light bullets. It’s the domain of 80-90 grainers only.
     
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