Possible headspacing issue?

3six7

Member
EE Expired
Rating - 100%
19   0   0
Location
Saskatchewan
This is my first AR and I had decided to build it, using one of the "Z" NEA lowers. I've finally finished it and the bolt will not close on a round. Everything seems to work fine with no ammo in the gun, cycles fine, everything. I've looked on the internet and have only found that maybe this could be a possible headspace issue. The specs of the gun are NEA lower, upper and bolt with a S&J barrel, all new. Another thing I've noticed is that the bullet does not seem to sit flush in the barrel, I am using a .223 rem FMJ to test, is this normal?I am new to the AR so excuse my ignorance. I was hoping to be able to take the gun out and test fire, hopefully someone on here can chime in and help me get this problem solved.
 
Try different ammo.

Check for dirty chamber or debris in the locking recess.

Headspace being too short is possible, but the least likely option. Try a different bolt and see what happens.
 
As c77 said, try a different bolt, every S&J bbl that was made in 2013 was checked by hand, all 854 of them and over 50 were test fired,
As for the other parts, I cant comment on that .
If not possible to test the product with other Mil spec parts, please send your upper parts, upper, bolt carrier and bbl to us for a full work up, no charge and we will cover the shipping both ways.
If it is our product that is defective, we will replace it at no charge too you
feel free to email us at sales@sjhardware.com
 
didn't buy a go and no go gauge? check some of the site sponsors. I picked up mine from Forester products out of the US.

if your using reloads check your sizing die, if its back off just alittle to much you wont get a full resize and then you have jammed rounds.
 
No, I was using a live round (no firing pin) to check. I ended up cleaning the chamber and pushing the bolt closed. After cycling and ejecting a few rounds it seemed to work ok. Might have been a tight ejector or some debris. Either way took it to the range to test fire, fired 12 rounds with no problems. Never tried zeroing anything in, only wanted to test function. So far happy with the gun.
 
No, I was using a live round (no firing pin) to check. I ended up cleaning the chamber and pushing the bolt closed. After cycling and ejecting a few rounds it seemed to work ok. Might have been a tight ejector or some debris. Either way took it to the range to test fire, fired 12 rounds with no problems. Never tried zeroing anything in, only wanted to test function. So far happy with the gun.

And I'm going to hazard a guess that there is good reason/possibility why you were not getting a proper smooth bolt lock up. The firing pin is what keeps your cam pin properly aligned.
 
Yeah, noticed that after removing the pin. Tried it with the pin in later when I was outside. I'm not going to pretend, I'm an AR noob. I will post again once I run through 100 rounds or so next weekend but the dozen rounds that were fired today had zero failures.
 
Yeah, noticed that after removing the pin. Tried it with the pin in later when I was outside. I'm not going to pretend, I'm an AR noob. I will post again once I run through 100 rounds or so next weekend but the dozen rounds that were fired today had zero failures.

also a good idea is to lube the hell out of the bolt and cycle it some at home, don't be nice to is #### it and let if fly.
you will see some wear on the back face of the bolt head lugs as its starting to mate with the bbl ext.
Do this about 50 ore more times then blast out any bits of dirt, metal parts ect and re lube.
This is something we have seen when using parts from different makers.
also after 50rds check you low profile gas block, some people set it to far back, most don't know that you need to set the gas block back 1 /32 of an inch from the stop on the bbl.
if you don't and the gas tube is a tad long then the gas key can push, the gas tube and little and loosen the gas block.
I have also seen misplaced and over length gas tubes, stop a round from fully seating into the chamber, thus acting like a bbl with an out of spec chamber.
First time I had this happen, it took me over an hour to work it out LOL !!
bbb
 
Yeah that's kinda what I did, disassembled the bcg, cleaned it again, re-lubed it and cycled the gun. Also made sure I could actually get a round into the extractor, it was kinda tight. I'll be sure to keep an eye on the gas block. Thanks for the help guys!
 
Back
Top Bottom