I heard someone had a problem. He is very concerned about this function. Its not intended. And he is very clear that he does not want this malfunction. So I thought I would ask the question here. The problem is, the PSA AR9 is going rapid fire. So they tried another PSA AR9 upper on the lower, the lower worked fine, so the lower is not the problem. Tried the bolt in a different upper, the upper worked fine, so the bolt is not the problem. Tried a different bolt in the upper. HAD THE RAPID FIRING PROBLEM. So the upper its self may be causing the rapid fire to occur. Any suggestions?
Some specifics would help. There are different versions on 9mm bolts and PSA has different 9mm uppers, so to trouble shoot we need to know which gen, which lower, which trigger, buffer system, etc.
My guess is it is the combo of trigger (more specifically the hammer) and bolt.
Edit: try this to see if the hammer is following the bolt:
Unload the gun first. Cycle the charging handle. Pull the trigger and hold it. Cycle the charging handle again. Let go of the trigger. Did the trigger reset or did the hammer follow the bolt? (I.e. can you pull the trigger and the hammer falls?) If it followed the bolt then that is your issue. The bolt is not resetting the hammer.
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There is NOT enough information here to troubleshoot this issue.
- It is NOT likely that it is the upper receiver…or the bolt carrier….could be causing the effect you are concerned with.
- Most “simulated” full auto fire is unknowingly induced by the shooter.
It can easily by done (unintentionally) when firing off a rest and very gently squeezing the trigger for an accurate shot……the gun recoils faster/ further than the trigger reset and when it stops on the shoulder and travels forward again the trigger is inadvertently contacted again. This repeats itself and a simulated full auto occurs.
Either way……you should use an iPhone on the “Slow-Mo” video mode and have someone capture the event.
Examining the video is the cheapest/fastest/easiest way to 1st step in diagnosing the problem.
Thank you for the suggestion. It reset and fired fine.
Ok, well give us some specifics:
Trigger, buffer system, is it factory or home built, etc? Pics would help also.
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PSA AR9 UPPER with Gen 4 BCG (package), Aero P. EPC-9 lower with PSA premium lower build kit with EPT. PSA AR9 5.5oz buffer
After a few rounds, the suspect system started to rapid fire, bursting 2-4 rounds per trigger pull. Avoided holding the trigger down due to concerns that the magazine would empty. The rapid firing would occure regardless of type of trigger pull (slow or fast compression of the trigger).
Determined 3 possible suspects:
- Problem with the lower / trigger.
group, etc. - Problem with the Gen 4 BCG
- Problem with the upper.
To test the lower, two identical alternative PSA GEN 4 AR9 uppers (with a known history of working) were used. The two alt uppers were placed on the suspect lower. A number of rounds were fired (through the 2 alternative uppers, on the suspect lower) no problems.
To test the PSA GEN 4 BCG the suspect BCG was pulled from the suspect upper and placed into one of the known, functioning, alternate uppers. This upper was then placed on the suspect lower and number of rounds were fired (using the suspect BCG through the known functioning alrernative upper) no problems.
To check the suspect upper, a known functioning BCG was pulled from one of the known functioning uppers and placed in the suspect upper. A number of rounds were fired and the FIRE BURSTS continued to reoccurre.
Using alternative uppers the suspect lower functioned fine. Placing the suspect BCG into a different upper the suspect BCG functioned fine. Placing a known functioning BCG into the suspect upper the problem reoccurred.
So the biggest issue I see here is you have mixed brands. Ar9s can be really finicky, and mixing brands can make them worse. Because of this, I have no idea other than to say you need to try the upper of a PSA lower with PSA parts. I have seen factory ar9 guns (that work 100%) mixed with other brands and have multiple problems.
Unfortunately, I don’t think PSA could help because they can do nothing with an Aero lower and your upper will probably work fine on a PSA lower.
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See below
It sounds like you have a disconnector problem or the hammer is not being cocked far enough to catch on the disconnector. The hammer can move back far enough to catch the sear but not the disconnector when the trigger is released.
I think Guitar Guy nailed it, you cannot “mix and match” 9mm AR components like a 5.56 AR.
Andy
The issue is probably bcg to hammer manipulation. Ramped, unramped, regular hammer or 9mm hammer. Mishmash of parts causes this.
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You have a described a Class III weapon, on the internet, think about it.
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No, they have described a malfunctioning firearm on the internet, and possible causes and solutions.
Has anyone checked to see if it’s as simple as a “sticky” firing pin? I had this exact issue on an old Marlin .22 at one time (dirty), and a friend of mine had a similar runaway-slamfire issue on a Norinco SKS (incorrect assembly).
Eliminate the simplest failure mode(s), then proceed. (but that said, I would be unsurprised if GuitarGuy had it)
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Mixing AR9 components is a bad idea. There’s a lot of proprietary stuff out there and even when it isn’t proprietary, the platform is so new that the lack of standardization is likely to come back and bite you at some point.
We recommend that your friend contacts our customer service department for a warranty issue. We have a couple of options that can be done. Since this sounds like a Fire Control Group issue, they can send out a new FCG if your friend is comfortable installing it themselves. OR, it can be brought into our repairs department were they will test, repair and re-test before shipping it directly back to the owner.
Here is the link to our contact page. It has our phone number, a way to email in, and our Chat function. There will be a few questions they will have to answer, then a label will be emailed to them for UPS to have it shipped back to us to fix. All at no cost to the customer.
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My bad, I was thinking of this case, had to refresh my memory.
DRABELS…….
it is NOT your responsibility to act as the PSA Forum Police !
Nor are you the ATF.
This is an adult forum for responsible gun enthusiasts.
None of your responses have even attempted to help the issue.
What is described here could happen to you….or anyone else in the firearms community.
It is clear that the owner is looking for alternative views to understand & resolve the issue described.
To put it nicely……think about what the objective is here on this posting….and respond….wisely…with help, if you can.
What is NOT needed is an ATF Troll……save that stuff for people you see face to face.
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@glbpellum please see @Joshlovesguns 's response above. Everyone else, this topic is done.
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This case involved someone who had a select fire firearm with the ability to fire on fully automatic. The OP has a firearm with a faulty fire control group. These to instances are nothing alike.
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