AR Builders: Ever get out of spec parts?

[shibbershabber]

I've been building ARs for 10 years now........

Never once have I had a problem.

Recently I've had two lowers out of spec.

1 was a TN Arms hybrid lower, the hole for the bolt catch spring/plunger was drilled too deep = no tension on the lever.

I had a replacement within a week. They were very good about it. This was the 7th lower from them that I built. Glad they took care of it.

Then, this week, I picked up a Noreen billet lower from AIM...
Something is off with the machining for the mag catch or the magwell itself is out of spec.
Using a Lancer mag, it holds... But if I pull it, it comes right out... Also if I shake it or insert a loaded mag... Falls right out.

Went back to Noreen in today's mail ...

Essentially TWO bad receivers in a month!

Anyone else?

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[JuglansRegia]

I think so, usually its been a problem getting the safety to work smoothly, I still need to figure out whats wrong with the last build but I believe its an out of spec part, it was a CMMG lower parts kit on a CMMG AR10 receiver so no excuses

 

[Geardo]

I got an out of spec BCG. Failed headspace and measurements.

MFG fixed it ASAP.

 

[jordanka16]

with the numbers being cranked out it is not surprising some bad parts sneak through. QC should catch them but I doubt anyone checks every part. As long as they make it right I have no issues.

 

[Member 34319]

I had at least one Anderson lower that was all funky. It went together hell or high water however.

CNCs that burn that many lowers have to be burning just as many tools. I'm curious how often tooling gets swapped or replaced, or how often they spec the machines.

Having seen the ultra precise machines that make parts for Intel as well as a manufacturing plant for firearms, I imagine the guys machining lowers all day are just pulling material in an out and running the sequence (or hitting the big button). With the guy that knows what he is doing, checking the machines, hopefully once a day.

 

[Alex V]

I have an otherwise inspec milspec buffer tube that is just about a quarter inch shallow on the inside. Just enough to cause issues with the bolt catch. Just doesn't work reliably. Rifle functions fine otherwise. I have a different tube, I've just been to lazy to swap it out.

 

[Caveman Jim]

Last year during my 300BLK pistol I had a problem fitting a LP gasblock. It measured .750 but it would not go onto the barrel!!! Brownells CS told me to get a dowel, sandpaper &to sand it till it fit.

I sent it back in a NY minute and lucked out finding a new Giselle LP GB for $40 and it fit perfectly.
Only one so far.... Knocking on wood.

 

[Geardo]

I've been building ARs for 10 years now........

Never once have I had a problem.

Recently I've had two lowers out of spec.

1 was a TN Arms hybrid lower, the hole for the bolt catch spring/plunger was drilled too deep = no tension on the lever.

I had a replacement within a week. They were very good about it. This was the 7th lower from them that I built. Glad they took care of it.

Then, this week, I picked up a Noreen billet lower from AIM...
Something is off with the machining for the mag catch or the magwell itself is out of spec.
Using a Lancer mag, it holds... But if I pull it, it comes right out... Also if I shake it or insert a loaded mag... Falls right out.

Went back to Noreen in today's mail ...

Essentially TWO bad receivers in a month!

Anyone else?

You build as many ARs as I wish I could!

 

[shibbershabber]

Well...

not as many as it seems...

Two this month, but the TN Arms one was bought in a bundle back in 2016, just now got around to putting it together... but with the build I did, it was too light, made the rifle feel unbalanced so I had to get an aluminum one. You know, down the rabbit hole.

I put the poly one up for sale, but given the political climate and the uncertainty of I-1639, I might just keep it.

 

[Johnny Tremain]

We had a mil spec buffer tube that was not turned all the way down.

My bud just finished his AR10, so I had to go do a function test. It failed.
It seems they pocket on the Stoner bolt release pocket was not deep enough.
It is now.

 

[shibbershabber]

I got the receiver back from Noreen. They took care of it pretty quick.

Got the new one assembled and ready to go.
Haven't fired it yet but everything works like it should.

 

[Jcon268]

I've been building ARs for 10 years now........

Never once have I had a problem.

Recently I've had two lowers out of spec.

1 was a TN Arms hybrid lower, the hole for the bolt catch spring/plunger was drilled too deep = no tension on the lever.

I had a replacement within a week. They were very good about it. This was the 7th lower from them that I built. Glad they took care of it.

Then, this week, I picked up a Noreen billet lower from AIM...
Something is off with the machining for the mag catch or the magwell itself is out of spec.
Using a Lancer mag, it holds... But if I pull it, it comes right out... Also if I shake it or insert a loaded mag... Falls right out.

Went back to Noreen in today's mail ...

Essentially TWO bad receivers in a month!

Anyone else?

Never had a lower out of spec but have had lower parts out of spec. Two safety selectors out of spec. Thought they all would be the same I was wrong. I am now using POF ambi safety selectors only

 

[HB of CJ]

Thirty five, (35) years ago when we were rebuilding beater M16 and M16A1 rifles for the Army Reserve, we ran across some USGI spec parts that were not. Just a few. We had all the gages and goodies and stuff to determine a parts goodness to go before we used it. Even then some parts were bad.

Later, commercially, and having build over 220 AR15 rifles, about 5% to 10% of the commercial and USGI parts would be non usable. A lot of my valuable time was spent gaging and setting aside part sets that would work together. Some parts required timely fitting. Some parts were just non usable.

Out of a built, (assembled) batch of ten, (10) guns, about 8 or 9 would go together. About ONE would be very sweet. About 8 or 9 so so. About one would take HOURS to fit. It finished up being very sweet but took too much time to build. I do not know about today. Precision has gotten so better.

Hope this helps.

 

[titsonritz]

Thirty five, (35) years ago when we were rebuilding beater M16 and M16A1 rifles for the Army Reserve, we ran across some USGI spec parts that were not. Just a few. We had all the gages and goodies and stuff to determine a parts goodness to go before we used it. Even then some parts were bad.

Later, commercially, and having build over 220 AR15 rifles, about 5% to 10% of the commercial and USGI parts would be non usable. A lot of my valuable time was spent gaging and setting aside part sets that would work together. Some parts required timely fitting. Some parts were just non usable.

Out of a built, (assembled) batch of ten, (10) guns, about 8 or 9 would go together. About ONE would be very sweet. About 8 or 9 so so. About one would take HOURS to fit. It finished up being very sweet but took too much time to build. I do not know about today. Precision has gotten so better.

Hope this helps.

Yep, 100% spot on. And that 5%-10% grows depending on which manufacturer is spec'ing and assembling them. Regardless of what people say/think not all AR's are the same, not by a long shot.

 

[titsonritz]

Never had a lower out of spec but have had lower parts out of spec.

Then you've had a small sample set.

 

[etrain16]

I had an Anderson lower that the mag catch slot in the mag well was off just enough that a magazine wouldn't seat in the proper place, so rounds wouldn't get stripped off the top of the mag. Pain in the rear to figure out what was going on, but folks on this forum finally nailed the problem.

 

[Caveman Jim]

Revival of the non fitting parts thread...

See anything wrong with it???
I was in the middle of the build and noticed it and not wanting to wait for a new one I pulled out my Gisselle LP SGB I was saving....

 

[Chaffee]

CMMG upper so far under an Eotech wouldn't even grip the rail
AERO first tap on the trigger guard roll pin with a nylon hammer sheared the ear off

Never had a problem with anything else, never dealt with Anderson

 

[v0lcom13sn0w]

i knew a guy who got an out of spec disconnector. you can guess what happened.

 

[OldTengu]

I got an out of spec BCG. Failed headspace and measurements.

MFG fixed it ASAP.

Same. Had one that had an out of spec lug and would lock on the bolt catch. Got a replacement no questions asked.