Finally finished my first AR

Advoc said:
I bought the upper completely assembled. I understand that Norc gas blocks are notoriously difficult to remove, so some people just cut the sight and bayonet lug off for a free float handguard ( like this one ), I don't know if he did that or not, maybe I should take a picture.
.......

OK.

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That doesn't look cut down to me at all, looks new. Is it just me or does it cant to the left, could that be a problem... I'd assume the gas port in the barrel is exactly on top right?



Only one mag, I just barely bought it, it's a brand new plane jane Pmag.

As for the test... What do you think?


Click to expand...

The bolt is inserted correctly, however it appeared to move to freely when you pulled on the bolt. Have you performed the ring test?

It does appear that something is canted, it's either the block or hand guard. I would bet it's the block which can be checked a number of ways. After disassembling the guard check to see if the last Allen bolt is aligned to a dimple in the bottom of the barrel. Most manufactures place this reference point to match up with the top side gas port hole. FYI the second or towards the bolt mounting hole is directly opposite to the gas port hole in the block itself.

Cycling can be dramatically affected with the slightest of misalignment between the GB and GP.

On a side note I would ditch the Magpul dummy rounds and purchase good "snap rounds"
 
Well, it doesn't look like your ejector is fouled up and by the looks of the video, seems like there is sufficient tension on the spring. I just used my trigger-pull weight gauge to check a new spare bolt I have. It took about 2-2.5lbs of force to compress that ejector spring. Unscientific of course.

The pic with the jam, it looks like the spent case is still seated on the bolt with the rim under the extractor. Were all the jams like that ie with the spent case on the bolt face?

For the AR gurus, is it possible for spent cases to get stuck/jammed onto a bolt face?
 
Update:

So I took it into the local shop and I have to say, somebody who has experience is probably the best tool you can have. He's worked on lots of AR's and lots of Norcs as well. He showed me how to replace the extractor spring, and then did it for me anyway. He has a specific spring he likes, and gets them in all the time. He even switches out the new rifles he gets with them, so he thinks it could be a contributing factor, since the ejector looks fine.

He asked me something I didn't think to check. When I fired that one shot that held open with the case sitting inside the ejection port on top of the mag, did the bolt lock open on the bolt release, or the magazine follower? He's thinking if it isn't an extractor issue it's probably a gas issue and that i'm short stroking. I tested it at home and sure enough, the bolt CAN catch on the magazine follower if it doesn't go back quite far enough. So if it is still being dumb day after tomorrow when I head back to the range to test it... There's one more thing he's somewhat confident might be the problem.

Based on the barrel profile (I guess?) he could tell there was an A2 style front sight on the barrel before (makes sense, it was a norc), and it's been replaced with a new gas block. He has noticed in the past that when the new gas block is butted up right against the thicker part of the barrel where there would normally be a handguard ring, it's just a tad too far back. The old gas block would have been a bit forward of that position because the ring would have been between it and the ridge in the barrel. So whomever installed the new gas block didn't leave that same amount of space between and just butted the GB up against the ridge. (does that make any sense?) Possibly cutting off the gas flow a bit by not having the port centered front-to-back, even if it is lined up properly with the cant of the barrel. I never would have thought of that.

Anyway i'll head out and test it again, He said everything else looked good. Gas rings are okay etc. if it's still giving me problems he told me to bring it back and he'd have a look at the GB.
 
Advoc,
I just emerged from a similar problem with my 10.5" AR. I had FTF and the same double feed as your gun.
My issue was solved simply by lubing the crap out of the bolt and carrier. Using Mobil 1 synthetic oil. The rifle went perfect after that.
I was told a heavy buffer also helps with short stroking but that's hearsay on my part.
 
It's a Norc 10.5 upper and BCG - it's a common problem, the extractor needs to be redone with an extractor rebuild kit; a spring, O ring and insert. No biggie. The factory parts aren't up to the job, it's a $10 fix.
 
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Advoc said:
I just read this tonight in some other threads. What weight? the lightest you can find i'm assuming right?

I just gave it a light coat of Hoppes 9.. I guess maybe my problem could just be not enough lube?
Click to expand...


the part of the bcg that needs lube is the inside. if you examine the inside of the carrier, you will see that it is very smooth, like a cylinder in an internal combustion engine, and the bolt has "piston rings" on it. this is the heart of the system. if the rings are worn or damaged, or if the inside of the carrier is damaged, gas will escape and the rifle won't cycle properly. do the bcg ring test: put the bolt into the carrier and see if it drops out of the carrier by gravity alone, point the bolt straight down. shake it to see if it will fall out. now move it by hand, it should be snug, yet will move in and out with finger pressure. if it passes the test, then make sure that the inside of the carrier is very well lubed. selecting lube is a bit tricky due to the wide range of temps we get here in Canada. I used to blend my own, but now I use Hornady One Shot, after reading a very comprehensive review of many different products. a few other products also did well, but One Shot is also very good for corrosion protection. anyway, don't be afraid to use a lot of lube inside the bcg, the excess will just blow out and cover your face if the wind is just right. hope you get your little eardrum numbing device running reliably.
 
Advoc said:
I just read this tonight in some other threads. What weight? the lightest you can find i'm assuming right?

I just gave it a light coat of Hoppes 9.. I guess maybe my problem could just be not enough lube?
Click to expand...
Hoppes is a solvent, not a oil. I normally use G96, but, yeah, lightest viscosity you can find for Mobile 1. You may have solved your problem, like mine!
 
Advoc said:
Update:

So I took it into the local shop and I have to say, somebody who has experience is probably the best tool you can have. He's worked on lots of AR's and lots of Norcs as well. He showed me how to replace the extractor spring, and then did it for me anyway. He has a specific spring he likes, and gets them in all the time. He even switches out the new rifles he gets with them, so he thinks it could be a contributing factor, since the ejector looks fine.

He asked me something I didn't think to check. When I fired that one shot that held open with the case sitting inside the ejection port on top of the mag, did the bolt lock open on the bolt release, or the magazine follower? He's thinking if it isn't an extractor issue it's probably a gas issue and that i'm short stroking. I tested it at home and sure enough, the bolt CAN catch on the magazine follower if it doesn't go back quite far enough. So if it is still being dumb day after tomorrow when I head back to the range to test it... There's one more thing he's somewhat confident might be the problem.

Based on the barrel profile (I guess?) he could tell there was an A2 style front sight on the barrel before (makes sense, it was a norc), and it's been replaced with a new gas block. He has noticed in the past that when the new gas block is butted up right against the thicker part of the barrel where there would normally be a handguard ring, it's just a tad too far back. The old gas block would have been a bit forward of that position because the ring would have been between it and the ridge in the barrel. So whomever installed the new gas block didn't leave that same amount of space between and just butted the GB up against the ridge. (does that make any sense?) Possibly cutting off the gas flow a bit by not having the port centered front-to-back, even if it is lined up properly with the cant of the barrel. I never would have thought of that.
Click to expand...

If you have the right sized roll-pin punches and tools, you can check the gas block alignment yourself.

- Remove your upper from your lower and remove the BCG
- Remove the handguard
- Use a pin punch to knock out the roll pin in the gas block that is retaining the gas tube
- Unscrew the gas block and remove the gas tube
- Remove the locking screw that is closest to the receiver end
- Rotate the gas block around so that the clamping screw side of the gas block is on the same side as the gas port
- Does the gas port line up perfectly with that of the screw hole on the gas block? If it is a clamping block, there should be a slight semi-circle indentation on either side of the slot. If so, the distance of your gas port/gas block is fine. Chances are the guy who did the original work installed the block misaligned.

Looking at the pic of your gas block, it looks like it is off to one side. Either that or your handguard is on crooked?

Anyway, you got an AR guy to look at your rifle now which helps a bunch.
 
Hoppes makes oils too I have both. It was definitely oil I was using not solvent. Although I would be happy to accept ridicule if I had thought I was using solvent to lube my parts. haha.
 
Thread Resurrection:

I FINALLY got out to shoot this thing again and I'm happy to report I put 50 rounds down range without a single malfunction. Smooth operation and bolt fully locked back with both types of mags I was using.

I'm going to tell you what I did to get it working, just understand this isn't what I'm saying everyone should do, it's just how it happened. and I'm glad it's working.

So I took to the shop, and he replaced the extractor spring with one that he says he uses in every AR bolt that he works on, even the new guns that they get in the store if the customer wants them.

I disassembled the handguard and took the gas block off, cleaned everything up on the mating surfaces with Hoppes and carefully put it all back together, not being too sure if I got the gas port lined up properly or not.
I cleaned the BCG with hoppes as well as the uppper, as much as I could. Then I lubed the BCG in 0W-20 Mobil 1, was very generous in my application. Racked the bolt a few times. Put it in the safe.
Pulled it out 6 weeks later. Cleaned it all off again. Lubed with Hoppes gun oil, almost as generously as with the engine oil previously. Took it out, ran like a champ.

The only thing I don't like about this gun is that I'll never get a 6NIA for it. I'm also not a huge fan of quad rails, but this one is short enough it works.

I got a SeeAll for it, which is super slick and compact. I just need to learn how to use it and get it sighted in. What distance do you usually zero your irons at?

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