Featured BB's curve left with Maple Leaf MR. HOP in multiple AEG's

Discussion in 'Gun Building, Modifications & Repairs' started by Peeque, Jul 21, 2021.

  1. Peeque

    Peeque Well-Known Member Supporting Member

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    I have the ML MR. HOP in three of my AEG's. Galaxy MP5k, Echo1/JG G36k, and a JG Stubby M4. I currently use 70° in all of them. I used to have the 50° in them too and they had the same issue. After 100ft or so the BB's take a hard turn left and go straight into the ground.

    I use BLS. 0.28g BIO.

    In the MP5k I'm using the stock hopup unit and the ML Omega nub. Krytac 6.05 barrel.

    In the G36 I'm using the stock hopup unit and the ML Omega nub. ORGA 6.13 barrel.

    In the M4 I'm using a MAXX ME hopup unit with it's own concave nub. I briefly used a Lonex hopup unit with the Omega nub before I got the MAXX unit. Still had the same issue. ZCI 6.02 barrel.

    I can tell when hop is applied that the patch isn't lowered evenly info the barrel. The left side is favored. That would explain why they curve left, but why isn't the patch lowered evenly? With no packing on the barrel I can see that the nub is centered to the window and is lowered evenly. So why isn't the patch?

    Maybe, even though the keyed part of the packing is in the slot on the barrel, the patch is not centered in the window.

    I will reply with pictures as soon as I can.
     
  2. Peeque

    Peeque Well-Known Member Supporting Member

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    Krytac 6.05 / MP5k - The left half of the patch is slightly lower than the right half.
    20210721_144822.jpg

    ZCI 6.02 / MAXX - Left 1/4 of the patch is slightly lower than the rest.
    20210721_145628.jpg

    ORGA 6.13 / G36 - This looks good, but curves right.
    20210721_151401.jpg
     
    Last edited: Jul 21, 2021

  3. richman992

    richman992 Well-Known Member

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    I feel like I remember Guges saying something about the maple leaf packings needing the window on the barrel filed slightly. However I have 2 AK rifles running MRHOP and Omega nubs that required no modification and work perfectly.

    I did have almost this exact same problem with a maple leaf chamber set for TM G series. I still have the complete kit sitting in a parts bin because the stock marui performed better.
     
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  4. Peeque

    Peeque Well-Known Member Supporting Member

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    Yeah he did say that. It's possible the ZCI and Krytac barrels aren't compatible with the packing.

    Maybe that's why the patch seems to look perfect inside the ORGA barrel compared to the other two.
     
  5. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    Yes...you need an enlarged window for the patch to come down evenly
     
  6. Peeque

    Peeque Well-Known Member Supporting Member

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    Enlarged in which way?

    Do you know of any barrels that will work without modification? I don't have a mill so I can't do it myself. I quite like the ORGA widebore barrel that I've been using with my F2. Are the ORGA barrels compatible? I don't know how the patch is supposed to look so I'm not sure if the ORGA's window is still too small or not.
     
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  7. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    Depends on the barrel...wider and deeper is needed.

    EDGI Barrel Window - Too Narrow

    [​IMG]

    The window gap should be ~.25mm wider than the hop-up contact patch.

    Here is a ML AEG Barrel

    [​IMG]

    See how the gap is Wider?

    Like the Orga

    [​IMG]

    But Orga barrels are not "well" made. Notice the bad finishing on this one and the inside consistency is pretty bad in the 3 I have looked down. You can see the extrusion lines in this one too and the burr in the window? You want to file that down so it doesn't cut up a packing.

    However, due to it being a wide bore, the gap between bb and barrel mitigates barrel turbulence even thought surface of barrel is not "smooth", which is good for accuracy.

    And here are 3 Krytac barrels, but you can see the window width is varying.

    [​IMG]

    Top barrel looks to be the widest. If yours is like the bottom one...its not wide enough.

    You can take a MR packing and map the contact patch...then..make sure the window is a hair larger than that patch.
     
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  8. Peeque

    Peeque Well-Known Member Supporting Member

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    I understand now, thank you!

    Filing downwards will make the gap wider because circle? The diameter gets wider as you get closer to the center.
     
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  9. Ben3721

    Ben3721 Well-Known Member

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    I'm surprised no one has said this yet. And some of you will disagree with me. First the window is important to if that packing will even fit and seat right. But...

    Most barrels have a poorly cut alignment slot for the packing. Thats that 1 inch cutout in the bottom of the barrel that sets the rotational lock of the packing. If it's machined even a bit off your maple leaf packing will not work perfectly. Talking a few degrees or so. Then the barrel c clip cutouts are typically not perfect either.

    I've yet to see any barrel with a perfectly aligned packing grove. Not even aftermarket barrels like pdi, lambda, laylex or zci are perfect.

    This issue isn't as noticeable with flat hops, r hops or even a normal packing. But with maple leaf packings, it's very important.

    Then there's other rotational factors such as barrel rotation inside the hopup or the outer barrel of a m4 being off rotational wise. Yeah another issue could be happening. But your saying it's performance is identical in multiple guns speaks for itself. Unless there is wind or unintentional tilting of of aegs sideways to level with unlevel ground.

    I'm pretty ocd when it comes to my hop ups, packings and lapped barrels. And for me, the maple leaf packing didn't met that standard.
     
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  10. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    You can also widen the window by thinning the wall.

    I know the issues Ben mentions above, but I have always been able to tweek a ML packing to work in any barrel & hop-up unit...variances and all.
     
  11. Ben3721

    Ben3721 Well-Known Member

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    One could also cut that strip off the packing and seat the maple leaf by hand since it basically locks into the window anyways.
     
  12. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    ^That too...ala tweek!
     
  13. Peeque

    Peeque Well-Known Member Supporting Member

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    I decided to try modifying rhe ZCI window with my Dremel. I've got my $30 out of this barrel already so if I ruin it at least I didn't ruin a brand new barrel.

    ORGA 6.13 Measurements:

    20210728_111116.jpg
    20210728_111212.jpg


    ZCI 6.02 Measurements:
    20210728_111055.jpg 20210728_111008.jpg

    The ORGA barrel is about 0.4mm wider/deeper than the ZCI. The MR. HOP packing seemed to work on the ORGA barrel so I tried to match the dimensions of that.

    Before: 20210728_110855.jpg

    After:
    20210728_142525.jpg

    BB's don't appear to be heavily influenced to one side anymore. The BB's are still very inaccurate and hop isn't consistent. Some will go straight down like there's no hop at all, others will go straight up like there's too much, but most of them are in that sweet spot where they go straight and then arc up towards the end before falling. I don't know if this is related to the window or it being a low quality barrel.

    I've bought a few Maple Leaf AEG barrels from TaiwanGun. I'm assuming ML's packings are compatible with their own barrels? Hopefully, they work better. If not I'll just switch to a different packing for the AEG's that can't use a widebore.
     
  14. OutlawAirsoft

    OutlawAirsoft Active Member

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    I wish I could say that...
    I have tried almost every combination possible in my ICS AKS-74 (MR 50, multiple stock packings and nubs, homemade nubs, etc.), but to no avail. Half the shots drop almost straight down and the other half act like there is no hop-up at all. Some shots don't even come out of the barrel. I'm starting to wonder if it is even a hop-up problem.
     
  15. GrimWolf0770

    GrimWolf0770 Active Member

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    Wow no one called it a bucking! Yeah! Wooo!
     
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  16. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    You need to try another brand of bbs. What are you shooting now?
     
  17. Ben3721

    Ben3721 Well-Known Member

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    The nub needs to be able to float freely and not too snug, or it will jump and stick randomly. The packing lips need to be clear of the feed tube, the nozzle tip or the inside of the packing needs to be tapered. A flat tipped nozzle to untapered packing lips equals crazy behavior. I would do all testing with a half full midcap at a low rps to rule out feeding related issues before messing with too much. Some mags also tend to lock in too tight, pushing the hop up unit and gearbox up a bit, this can cause the nozzle to kink and bind randomly.