Aero M5 Receivers not lining up

jb0311

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I’ve had good luck with their small frame receivers but has anyone ever have a set this far off?
EDB3D051-92DB-4A20-A6B2-A70D137E1809.jpeg

416B88C3-12BC-43DA-8623-EE4E4B448BF7.jpeg

6E3BB173-54A9-453F-A183-758E151D3010.jpeg


The front looks fine but I’ve never seen a set this far off before, even using shitty Anderson lowers for small frame builds. Too late to return anything from the dealer. Reached out to aero’s CS just to see what they say but not optimistic on getting anything swapped out since it wasn’t purchased direct. I know aero is basically budget but I would have expected better quality here. Can’t tell if the issue is with the upper, lower, or both. Is this going to be a purely cosmetic issue ? If it was just the gap I wouldn’t mind as much but the off-square has me a little hesitant to finish the build. Thoughts?

Will update if Aero responds to me.

Thanks,
 

celltech

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I have 2 M5 sets that line up perfectly with a minimal gap. Aero will make it right for you...
 
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msgriff

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No, my M5s look nothing like that.
Did you buy a factory complete upper? If not, who put the barrel on and how was the upper clamped?
Bore alignment could be off far enough that the carrier will be riding one side of the RE, so if you run it, keep an eye on wear. Also, check your tension screw, but that shouldn't twist it.
 
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jb0311

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Did you buy a factory complete upper?
No, stripped receivers purchased at different times. If I bought a factory complete I would have returned from the get-go due to the fitment.
who put the barrel on and how was the upper clamped?
Upper receiver has not been under any torque, barrel has not been installed, but I use a Geissele reaction rod when I do install barrels. Nothing but the FA and dust cover has been installed on the upper. It was like this from the factory.
Bore alignment could be off far enough that the carrier will be riding one side of the RE, so if you run it, keep an eye on wear.
Good point. I'm still waiting to see how Aero's warranty will handle this but I have more money in the barrel and trigger than in both receivers combined so at this stage I do not plan on proceeding with the build until I get a set that mates up better than this.
 

bfoosh006

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    No, my M5s look nothing like that.
    Did you buy a factory complete upper? If not, who put the barrel on and how was the upper clamped?
    Bore alignment could be off far enough that the carrier will be riding one side of the RE, so if you run it, keep an eye on wear. Also, check your tension screw, but that shouldn't twist it.

    I also would think the uppers bore alignment would be bad.

    Or maybe better said.. how far off can it be before the stuff starts binding or wearing badly / pre-maturely ?
     
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    Ravenworks

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    Who's pins are you using and does this happen unpinned?
    I had a set where the rear boss was about 2 thousands proud
     

    jb0311

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    Who's pins are you using and does this happen unpinned?
    I had a set where the rear boss was about 2 thousands proud
    Using a set of battle arms enhanced I had laying around. The rear take down pin was a little tight when installed so I backed the set screw out a bit but the receivers fit the same with or without the pins.
     

    Ravenworks

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    Well to be honest with you I've never seen this, I've dealt with many AP uppers and lowers.

    I did a search as well and found nothing.
     
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    Harman117

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    Aero recommends using their M5 LPK. It uses "custom" takedown and pivot pins.

    (Not saying this will necessarily fix the prob, but something to look into)

     

    DangerRanger

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    They are just slightly longer because the recievers are thick in that area. I built an m5 on a luth ar normal kit and the pins just don’t protrude far enough to push by hand and need to be pushed with a bullet. No other negative effects.
     

    BCP

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    Using a set of battle arms enhanced I had laying around. The rear take down pin was a little tight when installed so I backed the set screw out a bit but the receivers fit the same with or without the pins.

    I had to order an aero rear pin for mine because the dpms one didn't fit.
     

    jb0311

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    I had to order an aero rear pin for mine because the dpms one didn't fit.
    Ive got a set of the aero M5 pins as well that I could use but the receivers are just as off-square without the pins as they are with them.
     

    jb0311

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    Aero recommends using their M5 LPK. It uses "custom" takedown and pivot pins.

    (Not saying this will necessarily fix the prob, but something to look into)

    I do have a spare set of M5 pins as well but the BAD pins seem to fit fine and do not change the fit of the receivers when pushed in.

    Im going to see what Aero says (I put in a help ticket yesterday) and in the mean time try to figure out definitively if the upper or lower is the problem. The front of them lines up perfect but it almost seems like the rear of the lower may be causing the issue.
     

    Hobo Hilton

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    One more "sign of the times"... Tolerances (on everything) are not what they were 25 years ago.

    Take a file or sand paper to it and refinish it with a black Sharpie......... There won't be any fashion shows in the future... Make if functional.

    Hobo
     

    jb0311

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    Update as I believe in giving credit where it is due:

    Aero responded to my help ticket in a little over a day and are sending a shipping label for the upper to check first as that is most likely where the issue would be. Sounds like they will also have me ship the lower if MN allows to check fitment with new upper. That is quality CS in my book.

    Or I could take Hobo’s advice and sand paper and sharpie it?....🤦🏼‍♂️

    I will update again with any findings but thanks for the contributions.
     
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    Ravenworks

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    Obviously you have not read enough
    I read it and I'll respond the same way.

    Any time that I've dealt with Aero they've been a no bullshit company and the same goes for their parts.

    Like I said I've never seen problems with their receivers lining up.
     
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    Harman117

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    Obviously you have not read enough

    Unless you work for Aero and have been recording stuff for 25 years you can't make the statement you did. You have no clue.

    And if you're making a blanket statement on all manufacturing, then you're delusional
     
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    Hobo Hilton

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    Unless you work for Aero and have been recording stuff for 25 years you can't make the statement you did. You have no clue.

    And if you're making a blanket statement on all manufacturing, then you're delusional
    I stand by my statement.... You need to get out of the Aero basement and get into the real world of "mechanics"... Not just Aero stuff... Go restore a 30 year old Ford pickup, repair your wife's washing machine, rebuild the brakes on your car, fix your kid's bicycle... Step away from the computer...

    As for "clues" I'll put mine up against yours, any day.
     

    Harman117

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    I stand by my statement.... You need to get out of the Aero basement and get into the real world of "mechanics"... Not just Aero stuff... Go restore a 30 year old Ford pickup, repair your wife's washing machine, rebuild the brakes on your car, fix your kid's bicycle... Step away from the computer...

    As for "clues" I'll put mine up against yours, any day.

    I have a bachelor's degree in electrical engineering, and I work as a controls engineer for a major automotive manufacturer.

    Your statement is the same anecdotal bullshit that gets regurgitated by people who don't know what they're talking about. You literally have no clue, and think you do. Any given company can have quality control issues, but to say "Tolerances (on everything) are not what they were 25 years ago"? Really?

    Let me guess, you think scopes are getting worse too? You're sounding more and more like a fudd.


    Edit: Hobo hit me up with direct messages if you want to keep this going. Apologies to the OP for derailing the thread.
     

    Praetorian_6

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    Really glad to see Aero is taking care of you, even though it wasn't purchased from them directly. Good CS! I can speak for the 4 Aeros, including 2 M5s, that I've purchased without any alignment issue. The "they don't make 'em like they used to" portion of the thread is dumb and not worth wasting time on. Opinions are like assholes and shitty ones come from them, too.
     
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    jb0311

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    Really glad to see Aero is taking care of you, even though it wasn't purchased from them directly. Good CS! I can speak for the 4 Aeros, including 2 M5s, that I've purchased without any alignment issue. The "they don't make 'em like they used to" portion of the thread is dumb and not worth wasting time on. Opinions are like assholes and shitty ones come from them, too.
    Agreed on the CS. They even paid for the shipping which is above my expectations especially since I didn’t buy the parts direct as you mentioned.
     
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    jb0311

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    UPDATE:

    Aero received my set on July 22nd.

    I just received this message from Aero (4 business days later):

    "Hello Sir, I have decided to replace both the upper and lower as they both had tolerances near the edge of acceptance. This caused "Tolerance-Stacking." and resulted in the offset that you describe. I have matched an upper and lower and will be shipping them back FedEx 2Day"

    Hard to find a complaint with that CS. Perfect timing as it should get back to me about the same time as the SLR handguard which is the last part needed for the build.