ECHO1 M28 Technical

Discussion in 'Sniper Rifles' started by DRAGON64, Oct 30, 2012.

  1. DRAGON64

    DRAGON64 New Member

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    The M28 platform came out two years ago, and filled a void left by the lack of CA M24 rifles, as an affordable M24 platform. This rifle was released alongside other variants of the M24 platform, like the UK Arms, Snow Wolf and Javelin Gun Works versions, all of which helped to fill in the voids. The M28 generated rave reviews when it was released, with its low pricing and its available options.

    Now, generating a lot of negative press, the M28 is developing a rep as a platform to avoid. Even I have advised people against this rifle, as the rifle will surely disappoint anyone not ready for the technical problems that have plagued it since its inception. From a technical standpoint, I would like to re-evaluate the M28 rifle, looking at its good points and its faults and try to get the most correct and current information available. The information will be presented as plain and as clear as possible, in hopes of clearing up some of the bad karma that has been generated over the last two years.

    Thread rules: This thread is intended for technical issues, and problem solving. We will look at the latest parts available, and learn how to make do with the proprietary parts in the rifle. This is not a CA M24 or VSR-10 or JG BAR-10 comparison thread, and we will not make any distinctions between the different platforms. Since many of the parts of the M28 are proprietary, this rifle platform should be treated as a separate entity all together. Pics and video are a must and are highly encouraged. Feel free to share your experience with the rifle, share what you have had to deal with, and how you dealt with it... All M28 users are encouraged to participate.

    As this thread progresses, I will edit this first post with any additional updates, otherwise hit the subscribe option in the Thread Tools drop down box and follow along.

    M28 Availability:

    The ECHO1 M28, after two successful years on the market, the ECHO1 M28 now comes in two colors, the standard black, and now desert tan. And yes, the rifle comes with the following accessories as standard issue:

    • Two magazines
    • Harris style bi-pod
    • Barrel extension adapter
    • Tight bore barrel (6.03)
    • (3) Barrel Spacers

    Most of the top retailer such as Airsoft GI, EVIKE, Airsplat, Airsoft Atlanta and Pyramyd Air carry one or both variants of the rifle. There are many more venders, just too many to list, as they are easily searched online.

    One more thought, Airsoft GI and Evike have well stocked "Boneyard" links on their website that a player could pick up a spare M28 for parts. The cost is usually half that of the original. The stock and outer barrel are worth that price.

    Known Issues:

    • Plastic magazines miss-feed and poor fit
    • Slam-fire
    • Bad Hop-up rubber
    • Loose trigger sears (directly related to slam-firing)
    • Bolt handle breaks off at cylinder crimp location
    • Bolt / cylinder outer shell damage caused by out of spec receiver centering rings (may also contribute to slam-firing)
    • Some parts are proprietary, thus no after market support

    Currently Available Upgrade Parts:

    Note, EVIKE was marketing under the Matrix name, some cylinders and upgraded pistons, but these parts have proven to be somewhat unreliable and incompatable regardless of the description. For this reason, they are not included in this update.
     
    Last edited: Nov 2, 2012
  2. DRAGON64

    DRAGON64 New Member

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    Lets start the thread off with some encouraging news... Take a look at this video posted by Brian, the Echo1 USA lead tech. The video shows Brian repairing an M28 that is slam-firing. He replaces the trigger sears first, then the piston, and wala! The rifle is back in action... then watch a little further as he replaces the trigger assembly and piston with a 90 degree trigger assembly and pistion, that he says will be sold by Echo1... good stuff, here is the video:

    http://www.brianatecho1.com/videos/h...-vsr-10-parts/

    Here is the kicker; this video came out in May of this year, and as of this posting, I have not found any of the 90 degree parts available... but I'll keep looking.
     

  3. TornadoAirsoft

    TornadoAirsoft New Member

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    Yes I believe that when the rifle starts slam firing it's the parts in side the piston. I personally don't think its the sears. When I looked at comparison picture it looked really bad. I also looked at comparison pictures of the sears they looked fine. So this leads me to believe that the piston started the slam firing. So other than the piston being horrible and it's weight its a good gun?
     
  4. DRAGON64

    DRAGON64 New Member

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    In some cases yes, the plastic piston is doomed to fail as it gets warn with repeated contact with the meatl sear. But the Echo1 sear set installed in my rifle was so loose, with excessive side to side play etc, that any pressure from the spring would cause the trigger sear to leterally lay over, releaseing the piston. I rebuilt my trigger group with upgraded sears from Airsoft GI, and the problem went away. It was amazing to me how much tighter the upgraded sears fit into the trigger housing... night and day. Now with a better quality sear set in place, I had to break in the charging of the rifle, b ut after a few tries, the rifle worked great. I still have the stock piston in my M28.
     
  5. DRAGON64

    DRAGON64 New Member

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    I'll float one more issue that contributes to slam firing. Inside of the receiver are two plastic rings. The front ring is complete, and the rear ring has a gap in it. The rings help keep the bolt assembly centered within the receiver. But I have noticed that the rings in my m28 are a very loose fit. I was ablt to cock my rifle, and with some slight upward pressure on the bolt from my thumb, I could lift the bolt and the rifle would fire. Essentially I could fire the rifle, beause the slack in the rings allowed me to lift the bolt and piston off of the trigger sear.

    [​IMG]

    I fixed the rear ring by manicuring an old 35mm plastic film canister which I used to replace the rear ring. Cycling the bolt was a little tight at first, but it is wearing in now... Check it out:

    [ame]http://www.youtube.com/watch?v=uFK8ai09RJA&feature=plcp[/ame]
     
  6. DRAGON64

    DRAGON64 New Member

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    I emailed Brian (Lead Service Tech) at ECHO1 USA about the zero trigger and matching piston, and his reply was that ECHO1 was having them made, and they have been trying to source materials and parts... no ETA on these new items.
     
  7. EDI1st

    EDI1st New Member

    2,062
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    Fountain Valley
    For the record, E1 doesn't make anything.

    M28 = UK Arms M24.
     
  8. DRAGON64

    DRAGON64 New Member

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    After two years, I have decided to rebuild my own M28. There is nothing drastically wrong with it, as I have taken care of each of the issues as they have come up. But I purchased a new piston from Ranger Customs, and figured I would go ahead and break the rifle down and give it a good going through...

    [​IMG]

    Two years ago, I pulled my rifle down for the fist time to see what makes it tic, and I managed to strip one of the 3-small screws that secure the halves the hop-up chamber together... well, now is as good a time as any to fix that issue. I ordered a complete hop-up chamber from Amazon, and it arrived today...

    [​IMG]

    So my rebuild has begun!

    EDIT: I have been taking the time to make sure the M28 hop-up halves fit together uniformly, and it was brought to my attention that there may be "draft" issues with the part that has the hop-up arm pin molded into it. Essentialy, the hop-up halves are made from pot metal. The parts are cast into molds, and molds have to have draft built into them, or the parts will have trouble releasing, or will not release at all. One M28 owner pointed out to me that his hop-up arm pin was uneven due to the draft put on the part, and it was causing his hop up arm to apply uneven pressure to the bb. He stated that the base of his pin was thicker than the end. I did not have that issue as seen in these two pics:

    [​IMG]

    [​IMG]

    Remember, these rifles are cheap Chinese knock-offs, so the cheapest materials and processes are usually employed in order to sell quantity (not quality). With that said, I am making sure that my new M28 hop-up halves fit flush, by sanding down all of the flashing etc, that is left after the molding process. Because these are made from pot metal, it is almost like sanding lead... The bosses getting the most attention are circled in red.

    [​IMG]

    [​IMG]

    More as I have the time to write it.
     
    Last edited: Nov 3, 2012
  9. DRAGON64

    DRAGON64 New Member

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    The #1 Complaint With The M28... The Dreaded Slam-Fire

    The #1 Complaint With The M28... is the Dreaded Slam-Fire event. Until this issue raised its ugly head, the previous #1 issue with the M28 was the propietary assemblies, namely the cylinder group and the hop-up assmebly. This will be covered in more detail later; today's topic is the new #1 issue to plague the M28, and that is the slam-fire event.

    Again, for those of you just starting out, the slam-fire event happens when you cycle the bolt, and when you go to return the bolt to its fire position (battery), the bolt slams forward... wala, you have the nasty slam-fire.

    There are a number of theories out there about the exact cause with regards to the M28, I aim to describe the problem that caused my rifle to start slam firing. The issue with my rifle lies within original M28 trigger group. The major components that make up the assembly rattled back in forth inside of the housing. The parts, which are generaly cast pot-metal, were made with very loose tolerances. So loose, it was a wonder that the trigger sear ever held onto the piston in the first place. As seen in the next photo, the wear on the piston sear shows clearly the rounded edge...

    [​IMG]

    The piston sear flopperd around so much that when the bolt was cycled, the slot in the bolt was cutting into the side of the sear. Notice also how the metal looks almost pewter or even the color of lead. Pot metasl equals bad material for airsoft, unfortunately it is how manufacturers turn out quick down and dirty clones...

    [​IMG]

    Here is a brief video on my defective trigger group. Although the video is of poor quality, I am able to clearly show how bad the M28 trigger can be...

    [ame]http://www.youtube.com/watch?v=TmBhCv8xPxk&feature=plcp[/ame]

    There is an easy fix for this issue; if you are experienceing the slam fire event, and you believe that your trigger group is the problem, simply rebuild the trigger group... The downside is, it will cost you at a minimum of $55 for the parts. For my rifle, I rebuilt the trigger group using Airsoft GI's VSR-10 trigger sears and springs. The cost was $55 plus shipping. There are other manufacturers that make after market trigger parts for the 45 degree piston sear set up, you just need to shop around. I liked the Airsoft GI rebranded parts, as it comes with excellent spring package. You will find that the springs in the M28 trigger group are sub par, and need replacing. Here is the link to the parts I used:

    http://www.airsoftgi.com/product_info.php?cPath=362_364_651&products_id=5951

    Note also, if you are not comfortable rebuilding your own trigger group, then Airsoft GI has a complete upgraded trigger assembly for the M28, just remove and replace (R&R). Here is the link:

    http://www.airsoftgi.com/product_info.php?cPath=362_364_651&products_id=7694

    For those of you who seek the adventure and want to know more about what makes your rifle tic, here is a simple video I made on re-assembling your trigger group after rebuild. It is good to note at this point, that a trigger assembly from most any VSR-10 rifle will work in the M28. This is a blessing, as had this been one of the propietary assemblies, our rifles would have been dead in the water with no fix relief. As it is, this is the only complete VSR-10 compatable assembly that works as designed in the M28. Here is the re-assembly video...

    [ame]http://www.youtube.com/watch?v=OXbWbCUkgm8&feature=plcp[/ame]

    With any introduction of a new part, there is a break-in period, until the parts start to messh and begin working together. Give your new assembly some time, and it will work like it was supposed to in the first place. Brian at ECHO 1 USA has indicated in I video that I linked to, that there is a zero degree trigger and piston on the horizon... unfortuantely there is no release date set.

    If you have found that your M28 is slam firing for a different reason, please feel free to share what the problem was, and how you went about fixing it.
     
    Last edited: Nov 9, 2012