AR build issues

[AK0perator47]

You might check your settings, the 7 plus can take much better video. Although I swear I can see that you were shooting soft points?

No the one in that video was Hornady 223 Rem 75gr BTHP. I wanted to see if it was because of my usual match grade Tulammo that was the issue.

 

[Kruel J]

No the one in that video was Hornady 223 Rem 75gr BTHP. I wanted to see if it was because of my usual match grade Tulammo that was the issue.

Gotcha, well at least I was able to show it was a live round.

 

[AK0perator47]

Normal match grade ammunition that I use!

What is used in the video.
Actual round from the video!

 

[Kruel J]

View attachment 482898 Normal match grade ammunition that I use!

View attachment 482897 What is used in the video.
View attachment 482894 View attachment 482895 Actual round from the video!

That light primer strike reminds me of when I put a hammer spring in backwards once. Just sayin......

 

[AK0perator47]

That light primer strike reminds me of when I put a hammer spring in backwards once. Just sayin......

But that's the second round and the first one went down range. And I am quite sure that it is in properly. Why else would it eject a round when I pull the charging handle back and it ejected a round and then the next one chambered and fired? Rinse and repeat basically.

 

[v0lcom13sn0w]

sounds like a disconnector issue allowing the hammer to follow the bolt. also sounds like maybe the gas block hole may not be lined up perfect and the bolt is short stroking just enough to pick up a second round but not far enough back to catch the disconnector

i once had an out of spec disconnector that sent 30 rounds down range. its LONG gone now.i destroyed it and tossed it. not worth losing my rights.

that was fun(and startling). for about 3 seconds

does your upper fit snug against the lower or is there a gap there?

 

[AK0perator47]

Snug. I am willing to bet that it's the disconnector of the LPK. One of the guys here is sending me one.

Thanks @bolus

 

[v0lcom13sn0w]

now that i think of it, i had an anderson LPK that had a little ridge of whatever coating they use on the hammer where the disconnector grabs on to. it was causing a bind. wouldnt let the hammer reset as the disconnector stuck onto that ridge on the hammer. sanded it. polished it. put 1000rnds thru it.

 

[AK0perator47]

now that i think of it, i had an anderson LPK that had a little ridge of whatever coating they use on the hammer where the disconnector grabs on to. it was causing a bind. wouldnt let the hammer reset as the disconnector stuck onto that ridge on the hammer. sanded it. polished it. put 1000rnds thru it.

I always sand and polish my LPK just for this reason. Which is why I was lost when it happened but I never used Anderson before. I plan on getting a drop in trigger. Really don't want to spend $200+ for one. I been looking at Rise Armaments and Elftmann for under $200 and if...if I go over $200 then the Hiperfire. Just don't have any experience with Rise Armament.

 

[Mygrainman]

I'd bet that if you ditch that Poverty Pony FCG and replace it with a decent FCG, your problem would go away.

"Poverty Pony"
Love it!
As a Colt fanboy, I really can't stand the Anderson logo... I get that they are made in Kentucky, and the whole Derby affiliation, but I just can't get past it. My very first AR build was on an Anderson lower, and while it worked great(albeit with a rock river LPK not a "POV PONY") The first accessory I bought was an Ergo Never Quit Grip to cover up that hideous logo.. I think they got the idea and started selling lowers sans logo.

I can get just about any FCG to function great, and pull at between 4-5 lbs with a few tricks I picked up, so I haven't bought a drop in on over 20 builds.. I do have a Guiselle High speed national match in my SPR(18" Precision AR), but it pulls at just over a 1.5 lbs, with less than 8oz on the second stage. But I can get a dozen mil spec triggers for what it costs.

 

[Kruel J]

I have three Anderson lowers on the way to my FFL. Delivery ETA is Friday. $101 shipped.

 

[v0lcom13sn0w]

I always sand and polish my LPK just for this reason. Which is why I was lost when it happened but I never used Anderson before. I plan on getting a drop in trigger. Really don't want to spend $200+ for one. I been looking at Rise Armaments and Elftmann for under $200 and if...if I go over $200 then the Hiperfire. Just don't have any experience with Rise Armament.

i have a rise armament 434. its a really nice trigger.light, clean break and very short reset. i also have a CMC flat 3.5 i like it too. both were under $150

 

[DirectDrive]

But that's the second round and the first one went down range. And I am quite sure that it is in properly. Why else would it eject a round when I pull the charging handle back and it ejected a round and then the next one chambered and fired? Rinse and repeat basically.

1) That's why I posted that trigger animation in post #2
To get FCG install out of the way
2) When the hammer spring is in backwards, you'll get intermittent primer ignition
3) This is a common mistake

But I think you have a disco problem or something else is haywire with the FCG

 

[AK0perator47]

But I think you have a disco problem

I don't have a disco problem. No BeeGees for me! Next thing you know you're going to get @Kruejl breaking out some plats and strutting down the street singing staying alive!

 

[P7M13]

I've run into this before where the pin for the trigger + disconnect, and the pin for the hammer were sloppy enough that the trigger and hammer could be misaligned enough that the disconnector would not hold the hammer down long enough for the trigger to reset and the sear would not catch. To see this in operation, with the upper removed, I manually set and released the trigger over and over, and noted it would not catch once in a while. Got a dentist mirror and looked at it several times while properly engaged, and saw all kinds of misaligned engagements where I thought, dang, how is that holding? You could easily see the variation in how the disconnect held onto the hammer, sometimes not grabbing at all.
I replaced the entire FCG.

Doing it by hand, you cannot see the timing, but if there is any binding in the assembly, not allowing them to move in the time they need to, your trigger won't reset and the sear won't catch.

[edit to add] Based on your primer strike of the ejected round, IMO your problem is not that the disconnect got bound up, but that your sear did not engage properly. I had forgotten when writing, my trigger problem above also exhibited the symptom where the trigger would bind on the disconnect. To fire, you had to push the trigger forward to reset, and then fire.

Here's another good vid. At the speed the bolt is traveling, you can see that timing is in a pretty narrow window.

Poverty Pony FCG

LOL, never heard that one. I have two Poverty Pony LPKs and they all work fine. The only one that has jacked up on me was DPMS. I think with any budget brand, YMMV.

I always sand and polish my LPK just for this reason. Which is why I was lost when it happened but I never used Anderson before. I plan on getting a drop in trigger. Really don't want to spend $200+ for one. I been looking at Rise Armaments and Elftmann for under $200 and if...if I go over $200 then the Hiperfire. Just don't have any experience with Rise Armament.

As far as drop-in's, I believe Primary Arms just had CMCs on sale for ~$129, and you can buy Rise triggers for $99 on sale.
I have a Rise, don't know the model. Very light, short reset and same breaking point. If you go that route, they don't come with pins -- spend the extra $20 and get the anti-walk pins.

Sanding and Polishing :
I shudder at the suggestion, having seen too many times, the unintended consequences of someone's "polishing." What to one man is polishing, to another is removing miles of real estate.

 

[HB of CJ]

I once left the firing pin out of a build. Embarrassing. FWIW: Most lower fire control group parts today use cut back M16 disconnectors which needs the M16 disconnecter spring. The Early SP-1 Colt AR15s used a special AR15 disconnector. The springs are different. The M16 spring is about one half strength. The AR15 SP-1 disconnecter spring is double strength. They look almost identical. The difference in strength is an acquired experience thing. Easy to get the guts in the bottom mixed up.

I do not know about your build. Nothing more I can add.

Hundreds of builds and I still made mistakes Sometimes speelll chzk is a real hoot. Like right now.

 

[best defense]

I have just came back from the range. My AR build is able to fire the first round and it picks up the second round but, the trigger is dead. I am curious to know what is going on.

The lower is a Spikes Tactical with a Maxim Defense CQB stock. The upper is my Bushmaster 16" barrel.

I am not sure if it's the buffer or the trigger. Here is a video that may help. Anything else that would help you help me just ask.

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Here is one option, Since you imply that you built the gun, you should probably know how to remove the trigger, so if you removed the trigger and put in one of those modular triggers you might have better luck. There are a few companies that make modular triggers, so I won't suggest any one brand.

 

[CrackPipe]

I have just came back from the range. My AR build is able to fire the first round and it picks up the second round but, the trigger is dead. I am curious to know what is going on.

The lower is a Spikes Tactical with a Maxim Defense CQB stock. The upper is my Bushmaster 16" barrel.

I am not sure if it's the buffer or the trigger. Here is a video that may help. Anything else that would help you help me just ask.

There is a small spring between the disconnector and the "trigger". I believe that your symptoms match what happens if it is missing or not functioning properly.

 

[Core]

It sounds like one of you springs is not installed properly in the Fire Control Group (FCG). It may also be a QC issue with the FCG. Pull it and inspect springs, and re-install using proper procedures. I tend to agree that it might be a spring on backwards or the disconnect binding? When I install a FCG I do the military test which ensures everything functions prior to going live. Here's a good video: Installing the Fire Control Group On Your AR-15 they discuss the test at the end of the video.

There is a way to polish the FCG surfaces properly but you have to be careful as once you remove the surface hardening you ruin the component. Inspecting the FCG, springs is critical. Deburr. Polishing should only be done if you know what you're doing, and there is actually only one type of polishing cloth I know of that does the job right: ultra fine emery cloth or 2000 grit with generous amounts of oil to suspend sediment removed and prevent cutting too deeply into the hardened coating.

I use Colt Defense FCG's due to their high QC. BCM also has good QC and much more reasonable FCG prices and I have been told they are really good QC. There are also a bunch of FCG manufacturers who use the same manufacturer as Colt Defense, that have good QC. It's really all about the origin manufacturer, and the QC once the middle man assembles the FCG...

Mobile 28 grease is what I lube my FCGs with. I smear it on reasonblyheavy and do not have problems, ever. Also Larue is having a sale on their high end FCG kits, until this winter. Don't waste money on a drop in trigger unless your'e shooting bulls. Good luck!

 

[sed]

I always sand and polish my LPK just for this reason. Which is why I was lost when it happened but I never used Anderson before. I plan on getting a drop in trigger. Really don't want to spend $200+ for one. I been looking at Rise Armaments and Elftmann for under $200 and if...if I go over $200 then the Hiperfire. Just don't have any experience with Rise Armament.

Check out the LaRue MBT - it's a great two stage trigger. They're on sale at $87 until Christmas. That's a screaming deal for a great trigger!
The other "value" high quality trigger I like is Geissele G2S. Those can be had for around $110-120ish during good sales.
If the G2S and the MBT were the same price, I'd take the MBT - I think it's a better trigger.
Having the MBT be quite a bit cheaper than the G2S, it's a no brainer...MBT all day long! Anyone looking for a good two stage should be getting the MBT at $87 (IMHO) .
Good luck and enjoy!