Pudge
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So, finally got to shoot the AR. 300 Blackout, Anderson stripped lower filled with Aero parts, and a complete Aero upper. Short stroking issues, any suggestions?
School me on ARs, please - looking to purchase first
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ECVMatt
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I really know very little about the AR compared to others here, but I would guess buffer weight/spring, gas key/gas tube fit and possibly ammo. Were you shooting full velocity ammo or subsonic? What buffer to you have in the gun? Does the gas key properly fit over the gas tube and is it staked correctly?
Flame suit on, waiting for the response from those much more knowledgeable than me.
Flame suit on, waiting for the response from those much more knowledgeable than me.
Pudge
Member
For the buffer and spring, how would you know? Aero parts
The other issues would be QC from aero, correct? The upper came assembled.
Ammo: Fiocci 150 grain 1850 fps
The other issues would be QC from aero, correct? The upper came assembled.
Ammo: Fiocci 150 grain 1850 fps
Megawatt maker
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Were all the Aero parts from a kit? Or did you gather up the parts individually?
Reason I ask...carbine length upper with rifle length buffer tube and buffer...etc....if it was a kit..unlikely to be it...
Megawatt maker
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Adjustable gas block?
Pudge
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How would I know, and if so how would I adjust it?
Megawatt maker
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do you know where the gas block is? Its on the barrel...somewhere around the middle or so...tube comes out of it and goes into the chamber area.
If the block is adjustable...they will be idem that looks like an Allen head...or Star bit (depends on different brands)...if it is adjustable, turn it all the way in...then shoot..then turn it out...shoot...keep doing it a little at a time till the rifle cycles reliably
Megawatt maker
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It looks like this...
Megawatt maker
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Just be aware...sometimes they are opposite too...turn out will cut the gas off, and won't let the rifle cycle...it all depends. I have no experience with how Aero does it...so it will take some experiment to determine which way yours needs to go.
Skylerbone
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Knowing the cause is key. Underpowered ammo, too heavy a buffer/spring, misaligned gas block, leaking gas key, underlubricated.
Those are the things to check. Easiest things are buffer weight, likely a carbine or H which should not be an issue. 37-39 coils for the spring, count them. My money is not on the gas block, let’s skip for now. Pull the bolt and check around the base of the gas key for leakage. Spray a little oil around the base, close your bolt, and blow into the tube (clean it first or it won’t taste good). If you see bubbles, it’s leaking. Learn how to lubricate your bolt correctly and try again.
My only failures with an Aero upper stemmed from over exuberance. I got to the range with my new 7.5” upper, new lower, and new bolt, zero lube. I pulled the bolt and added CLP, no bobbles since.
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Megawatt maker
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@Pudge...ya...do exactly like @Skylerbone said..
I'm expericed, but he has more. If that doesn't work...come back.
I'm expericed, but he has more. If that doesn't work...come back.
Pudge
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And this is why I asked here (and hijacked the thread), thanks. Buffer is carbine. No bubbles from the bolt. I'll look up how to lube an AR bolt.
Pudge
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So, plenty lubed, functions fine, but won't hold bolt open on an empty magazine (pmag). Will do it manually, but not on last round.
Megawatt maker
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Try a different mag
C-grunt
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Check your gas key on the bolt carrier group. Make sure it's secure on there and you dont have a lot of leakage.
But most likely you just need to adjust the gas block a little. If it's cycling and just not locking the bolt back that means it's pretty close to the proper setting. Aero should have instructions on how to do it.
Skylerbone
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I don’t think he has an AGB, never seen one on a complete Aero upper. Still no report on the spring, but with a carbine buffer seems odd that even an extra power spring with that combo would prevent cycling. That leaves underpowered ammo and possible issue with gas block alignment or gas port size.
C-grunt
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Ahhh, I misread the pics above as being his rifle.
Pudge
Member
I messaged Aero about the issue, and they've been pretty responsive. There's someone else dealing with the same issue using the same ammo, so we'll see where this goes. I'll be looking for some different ammo.
Skylerbone
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While it isn’t the ultimate solution for accuracy, I’ve developed what I call my EOW load that cycles all of my ARs without issue. I do have a few alternate loads for accuracy in specific rifles but I don’t worry about AGBs relegating any of them to single-shot status when running my bulk stash.
Hope Aero gets you squared away or perhaps they can procure some of the ammo lot in question and test things in house.
Hope Aero gets you squared away or perhaps they can procure some of the ammo lot in question and test things in house.
Pudge
Member
I'm going to be honest, I think much of the cycling issues were lube related. I think the hold-open issue can be resolved. It may be ammo. I know .300 Blackout with its wide range of bullet weights and velocities can cause issues for a semi-auto. If Uncle Joe would release my suppressor, it might work just fine with the ammo I have. In any case, I need to get some dies and start building ammo that will operate the rifle properly.
Pudge
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Manually it locks with every magazine I try, but not the last round for 3 different magazines (2 pmags, one metal Center Industries Corp.).
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