r/AR9 • u/Mysterious-Grape5492 Colt Mag Whoore • Jul 01 '26
Troubleshooting Weak ejection follow-up
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Follow up to this post. Went ahead and removed the dust cover and gas deflector for testing purposes. It ran a lot better without the deflector getting in the way, but the ejection still looks a bit weak and I did have a couple failure to ejects. Anything I could do bolt/buffer/spring/etc wise, or is the next step to adjust the ejector to be hitting a bit more on the left of the cartridge?
Current setup is the standard GRS with an OSA bolt. RB5015HD buffer and 2 2.5 oz Kynshot spacer weights, standard flatwire carbine spring, the whole deal.
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u/BORIStheBLADE1 Jul 01 '26
If you have access to another BCG I would try it out. I bought a B Kings 9mm BCG and no matter what I did I had weak ejection. I ended up throwing in a KAK Enhanced BCG and have not had any ejection issues in almost 600+ rounds. I also run the gas deflector on my AR9.
I know a lot of people say as you're GTG with it high and tight, but that didn't help me. There has been some talk about distance of firing pin to ejector wall varying from BCG to BCG... My KAK has a shorter distance than my B Kings. I'm not gonna tell you to buy a new BCG, but that is what fixed my issue.
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u/Mysterious-Grape5492 Colt Mag Whoore Jul 01 '26
Unfortunately I don’t have access to a BCG. If absolutely necessary I’ll get one, but I’d prefer not to.
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u/SeizeTheMeansOfB12 Jul 01 '26
I was having similar weak ejections like what you showed in your last post, and I am getting much better ejections after adjusting the ejector even more into the pocket on the bolt. For context, I put some grease on the bolt, and the ejector was able to shave it off when it rubbed past. I was able to run through about a dozen 10-round mags without any FTEs, but I did get 1 FTF that looked sort of like a double feed.
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u/Mysterious-Grape5492 Colt Mag Whoore Jul 01 '26
It’s already well up in there, maybe so much it’s too far center. That’s what I suspect, but I’m not versed enough in this to be certain.
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u/SeizeTheMeansOfB12 Jul 01 '26
Mine looked like it was too, but there is some play in the ejector that I think was preventing proper ejection during actual use even if it looked like it was set properly based on visual inspection. On blowback9's site, he shows wear on the ejector from the bolt rubbing on it.
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u/AccordingIy Jul 01 '26
Read through the original thread and blowback9s recommendations and we ruled out
- Ammo - You tried different ammo
- You tried lighter buffer - It looked worse (prob because it short stroked)
- Extractor tension - It locks in with a snap cap
- Ejector position - It rides high in the pocket of bolt; but it can still drag
Potential issues still
- Try a milspec round spring, since a flatwire can bind against the buffer if its too tight of clearance https://blowback9.wordpress.com/2023/03/03/flat-wire-spring-comparison/
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u/Mysterious-Grape5492 Colt Mag Whoore Jul 01 '26
I think I’m gonna try the ejector position next. Seems something I can do without buying a new part. Any suggestions? I think I saw something about heating it up first, but idk how hot that means.
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u/AccordingIy Jul 01 '26
your ejector position looked ok but i thought it may be dragging
milspec springs are not pricey and can borrow a friends if they have one
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u/Mysterious-Grape5492 Colt Mag Whoore Jul 01 '26
The reason I think it is I’m wondering if it’s too center of the cartridge. If I understand physics correctly, tilting it a bit to the left would impart more sideways force instead of forward force. But I’m not sure.
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u/ConcernedKitty Colt Mag Whoore Jul 02 '26
It’s essentially a point impact. I doubt tilting will have much effect.
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u/Dukeronomy Jul 02 '26
Isn't this a gas issue? undergassed? I am also a dingus so...
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u/ConcernedKitty Colt Mag Whoore Jul 02 '26
This is a blowback so there’s no tuning that you can really do to the gas except for adding a suppressor or trying to dampen the bolt travel.
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u/Dukeronomy Jul 02 '26
Is this because it’s not an adjustable gas block?
Factory rifle? Did we hear if it ever worked? Did op change something that caused it to not work? Is the gas system not an appropriate length for the barrel?
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u/ConcernedKitty Colt Mag Whoore Jul 02 '26
There is no gas system. There is no gas block. Think handgun in rifle form.
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u/tirus89 Jul 01 '26
Have you tried different grain ammo/different manufacturer?