So, I bought a hardened arms upper 10.5 and have had it out to the range 2x now.

I've been getting failures to extract the spent case. It will cycle the next round up but doesn't eject the fired one first.

I though it may need a heavier buffer so I put in a h3 buffer and an enhanced extractor spring with rubber washer. Still doing it. 1st round fired it gets the FTE.

Am I looking at a gas tube problem?


Edit for additional info:
Ammo used was remington, wolf, and federal (all 55 grain) All same issue. Mags used was battlemag and multiple pmags.

Bolt is a NiB Aimspurplus m16 bolt.
Buffer is around 5oz (I think)

Edit 2:  I forgot to check if it is short stroking . I'm guessing there is no way other that loading one round in the mag and firing

I had the same problem with a short barrel too. I put a o ring on the ejector spring and it fixed the problem.1/8" inside diameterx1/4" outside diameter o ring.

I thought it would fix mine. I pulled out the BCG and it already had the o-ring on it. I went ahead and replaced the spring and o-ring with an enhanced spring but that didn't seem to help.

What buffer spring, tube etc.?


I have a 7.5 hardened arms upper and it runs like a champ with any ammo I use including tula. I use the phase 5 hex 2c tube, phase 5 spring, spikes stt2 buffer, PSA premium bcg, and I have a grg krink brake on it.





Try running some mil spec ammo and see what happens. If it is a gas problem I'm sure hardened arms will make it right, they have good cs.





ETA: My BCM 14.5 middy did this to me at first when I used "factory" reloads. It worked fine with xm193, m855 etc. I never changed anything on it, just cleaned and lubed it up and ran about 500 rds of good ammo through it, lots of mag dumps. Now it works fine with pretty much any ammo, haven't tried tula yet but I will, I've shot wolf and no issues. BCM tells you not to use crappy ammo, but I like to shoot anythng...

Curious - what kind of bolt/extractor do you have?
Is the extractor Nickel/Boron coated?
If so, try changing the extractor to something that isn't nickel/boron

Does it do it when you just manually cycle the bolt or when actually shooting?

It's NiB.

I switched it out and it still did it.

Just shooting. I can manually extract most of the time. I think maybe once or twice it failed to cycle.

Have you checked the chamber? Any scrape marks on the fired brass?  Compare a manually extracted case with a fired case, any marks?

I just got my 10.5" upper from them yesterday. I will be hitting the range tomorrow(Thursday) to see how it functions. Will update you and let you know if I'm having the same issue.

Just looked on ups site and tracked my 10.5 it said it was on truck for drop off today so I will have a review in the next couple days too

my 10.5 upper came in today . got it put together grabbed a mag and a box of ammo 20 rounds and headed out the door .  went in the woods behind the house just to shoot it . it didn't have sights on it just wanted to see how it would do as far as ejecting and loading next round . took it easy on the first 5 or 6 just to see how she was doing then dumped the rest ran perfect no issues . going to go to the range sunday with my son and some friends . will post sunday how it when we get  back

Well I was able to get to the range today. First thing I noticed was the bolt wasn't catching on the last round to lock open. Then shortly after that I started having FTF issues. I took it apart right there and cut 2" off the spring. After that had zero issues till I got home. Once I got home I noticed a bunch of the screws including the one that holds the handguards in place. So I figured I'd just take it off to see how it exactly works. Well once I got the handguards/rail off I noticed my gas tube was a bit loose. The 2 screws that held the gas block in place were already working themselves out. Well I locktite(blue) on everything.  I will post Sunday once I get back from another range session.

As of right now not too impressed with the upper. It shot great and zeroed fine. No issues there on that end. Just looks like my son could have done a better job of assembling it. Well off to bed. I have the ironman competition in the morning!

I was able to make it to the range this evening also .  my 10.5 hardened arms upper ran great no issues what so ever . we shot 200 rounds .I have the sig buffer tube on it I bought the one that the tube came with the brace  I cut the little tit that sticks out on the bottom so I can attach my sling standard spring and heavy buffer not sure of the weight spikes m16 full BCG . I think im going to pull the hand guard and check the gas block after you said that yours was loose . going back to range tomorrow if I get off in  time or sunday for sure I post I if I have any issues

Went back to the range today and zero issues. Blue locktite is your friend! Everything functioned as it should. Did some rapid fire drills and slow fire. Not one hiccup. All in all I'm satisfied with my new AR pistol.

Sounds like Hardened Arms is one to stay away from.

But honestly, I had already guessed that.

Other than having to tighten everything, it's actually a decent upper for the price. I know you shouldn't have to do all that, but what are you gonna do? I'm going to be contacting them tomorrow to see if I can chat with their assembling crew. Hopefully they can nip this in the bud and no one else experiences this. I know all manufacturers have QC issues, even the big companies ie: remington.

went back to the range today put about 300 round though my 10.5 hardened arms upper today ran her pretty hard no issues  2nd time I have been to the range with my new build . got home took it all apart to clean every thing was as it should be  no loose gas block no issues at all . 100 percent happy with mine