AR Question

[suitableperson]

Took Nes 371 2009 lower and put in LPK and Geiselle trigger and put on buttstock. I sent it to Les Baer for a custom upper.
I am having some feed problems. Is this normal while it breaks in? Tried different mags.

 

[01SVTvert]

No, not normal. I have had 3 built lowers work perfectly out of the box. Parts on an AR shouldn't need "breaking in"

Question: Are you running the gun wet?
What type of mags are you using and are they in good shape?
What type of feed problems? Fail to extract? Fail to feed? Double feed?
Did the spring and buffer come with the stock and are they the correct length spring and correct type buffer?

Describing the feed issue may help.

 

[Skald]

As 01SVTvert said, hard to diagnose the problem without a bit more information.

One thing you may want to look/invest in are the magpul followers that supposedly help with feeding issues, but my ARs worked right out of the box,and I ran them pretty hard first day on the range (120 rnds in a few minutes in each) and only problem I had was ammo (solid primer hit, and I was using Brown Bear ammo).

 

[suitableperson]

No, not normal. I have had 3 built lowers work perfectly out of the box. Parts on an AR shouldn't need "breaking in"

Question: Are you running the gun wet?
What type of mags are you using and are they in good shape?
What type of feed problems? Fail to extract? Fail to feed? Double feed?
Did the spring and buffer come with the stock and are they the correct length spring and correct type buffer?

Describing the feed issue may help.

The gun was wet. Tried a few different mags,they all are in good shape. Some failed to feed,some stuck feeding at an angle and ruined the cases.
Stock and spring were new and came together. Are there different spring tensions? I was shooting my reloads. My other AR was eating them fine. Maybe it was the ammo?

 

[Admin]

How long is the upper?

 

[MassMark]

How long is the upper?

Yup - upper length, gas system length, (carbine, med, full), buffer tube and buffer details and barrel/BCG details would be helpful.

Anyone who tells you the gun needs "breaking in" to function properly is full of poo....

 

[PatMcD]

If it's a Les Baer upper, I know you paid a lot for it. Call them and see what they have to say.

 

[suitableperson]

The specifics.
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[suitableperson]

Agreed it should not need "breakin". They sent me a ten shot target they shot after they fit the upper to my lower. Impressive. Yep, I did pay alot. I'll call them if some factory ammo jams. I didn't have any to try. My reloads have never caused me any problems but who knows.

 

[MassMark]

It's possible you have a chamber issue...Try some factory .223 or some 5.56 and see if it clears up. Is your BCG an AR-15 group or an M-16 group?

 

[01SVTvert]

Fail to feed and stuck cases MAY be indicative of low power ammo or spring / buffer issue. Are you using a full length stock buffer tube or a collapsable length buffer tube? They each have different spring requirements as well as different buffers.

If you have the same type of stock as your other rifle, try swapping the spring and buffer from the good rifle to the other one. I would also suggest looking at overall length if it is different from the "good" one.

I will look to see where my info is on overall length for each.

 

[FalArAk]

Eliminate the easiest to diagnose problems first..

1) What kind of ammo (try factory)

2) What kind of mag

After you eliminate the easiest things,then you can start to work on the harder things.