AR Pistol Woes!

lazerblazer · Feb 5, 2013

An AR Pistol Stop gap to the SBR game. My troubles started from time of my receiving of the 7.5 AR upper. I had ordered this online from a company who I had done business with in the past. Since I had been running a 16 AR upper for over 1000 rounds from this company I felt I trust some more of their products.

Well upon opening the package first thing I noticed my heart sank, no lo-profile gas block with carbine length handgrip that I expressly paid extra for! So immediately I get into touch with them and then have wait another week to before I have it back in hand in the configuration I had hoped and paid for!

So I promptly hit the range, 3 weeks later. Hoping all the hype and wait would exceed my expectations I squeeze the trigger as I bring up my sight picture down range. After the first shot is off I to see a double feed from the first shot as well as the case being stuck in the chamber. The case looked over expanded the rim was sheared off by the extractor. What was the problem, so I clear the jam and start to fire again 1 more shot, same problem. I take a few more shots after that same story I was so crushed.

7.5 AR upper is sent back to the company with a similar explanation and the few casings from the test firing I had done. I then receive the upper back promptly and I feel that my troubles are over boy are we just in the thick of it! I get out to the range this weekend and start to the fire the pistol I get clean fire, extraction and ejection of the first 3- 5 shots then I start having no extraction at all. My 7.6 AR upper has now become a single shot pistol with no movement of the carrier after each shot but nice smooth extraction and ejection of each round when I use CH.

What shall I do with 7.5 AR upper that I want to work so badly? Do I just keep sending it back to see if my problems get fixed or should I just scrap the pistol? I could just make another carbine, but I really would love to have a short-barreled AR of sorts. Is there a barrel length out there that works in a pistol platform while being concealable?

I need the help of the NWFA community ASAP thanks!

-Lazerbalzer

civilian75 · Feb 5, 2013

When you start having extraction failures, what kind of extractor marks can be seen on the brass rim? How do you remove the stuck brass? Is it hard to remove from the chamber? Can you see extruded extractor marks on the case head?

Also, since you have another upper, try swapping the BCG to see if you can isolate the problem to the barrel/bbl extension or to the BCG.

iamme · Feb 5, 2013

What do you do with a 7.5" upper- Hope it's a 9mm or similiar cal, or sell it and by a 10.5" from a quality manufacturer. There's a reason you don't see much from the big names this short.

AR's that short get way overgassed and can just be problems waiting to happen.

Mattofsmatt · Feb 5, 2013

Put a single round in a magazine and shoot; if it fails to hold the bolt open, then you know the pistol is short stroking. A buddy of mine had the gas block come loose after a few rounds on his new pistol upper, and it behaved like you described: bolt-action AR.

KalamaMark · Feb 5, 2013

Since the empty cartridge extracts easily using the charging handle, and you have no movement of the BCG, I'd check the gas key on the bolt carrier and see if it didn't come loose. I've had one that wasn't staked properly work loose after a dozen rounds or so. I'd also double check the gas system, starting at the alignment of the gas block to the gas port at the barrel, the tightness of the gas block to the barrel, the tightness of the gas tube to the gas block, and the engagement of the gas tube to the gas key on the bolt.

It sounds like the gas you need to cycle the bolt is escaping before it forces the bolt back.

lazerblazer · Feb 5, 2013

Thank you for all the replays thus far it has been very helpful.
Upon removing my handguard I was simply able to slide the gas block with ease back and forth on the barrel. I noticed that the barrel has no detents for the allen screws, this seems to be a problem... Where do I go from here? How do I make sure I have the correct alignment of the gas ports. What is the best way to keep those screws set?

-Lazerblazer

iamme · Feb 6, 2013

Without a dimple it should hold reasonably well, adding the dimples isn't the hardest thing in the world just make sure everything is working and lined up properly before.

There's a million different methods to line up the GB and everyone has their own preference of what works best.

lazerblazer · Feb 6, 2013

I think i have good alignment, how do i make sure my gas block stays put this time? It is a low profile type with 2 set screws in the bottom. Once my GB is set then i can check to see if there are still function issues with this upper.

OREGON FALER · Feb 6, 2013

I will start out by saying I'm far from an expert on gas systems. I will add that I've been running a Bushmaster 11.5 inch upper for 4 years now with zero malfunctions, excepting only in my .22lr converstion, which malf all the time.

what company's product are we talking about here? I'd be tempted to just send it back and get your money back, if thats still possible.

And, there is a technical forum for AR-15 pistols over at AR15.com

lazerblazer · Feb 6, 2013

I have no idea if i can return but even if i do return, will i ever be able to buy again? That is the dilemma i am in, i feel that if all else i can just swap out the 7.5" BBL for a longer one. A new BBL and gas tube are much easier and cheaper to come by i would think at this time of the game.

Noveske CQB Match Barrel AR-15 Pistol 5.56x45mm NATO Medium Contour 1

OREGON FALER · Feb 6, 2013

Yeah, there aren't as many issues with the 10.5's & 11.5's but if it's a 7.5 you want then I'd get over to AR-15.com and make an account, put up pictures with a thread sorta like this one. There are many people who have those 7.5's that do work and it'll work for you, you're not cursed or anything.

iamme · Feb 7, 2013

Who is the maker of the parts you have?

lazerblazer · Feb 16, 2013

update: today after tightening all the set screws on the gas block I was able to run through a whole 30 rd mag with no issues. Needless to say I was so excited thinking this purchase was really going to payoff after all! After shooting the my 16in rifle I picked the Ar pistol up and loaded a 10rd mag. Three shots later no ejection, no cycling of bolt. I see that gas block has conveniently shifted forward again. My plee is for someone to help me dimple my barrel and rocksett it, in exchange I will give you 3 22's. 22 oz beers that is pending you being 21 yrs or more in age. THANKS!!!!:beer::beer::beer:

Sent from my Galaxy Express!

SCARed · Feb 17, 2013

Run down to Curts in Milwaukee on Thursday. He'll get you taken care of.

phatdoughnut · Feb 21, 2013

Glad you fixed your problem. I've been running a 7.5 model 1 sales upper for a while with zero issues using brass.

308 · Feb 21, 2013

You can always get the GB set where it is supposed to be, and consistently feeding/ejecting, then mark it in place, run a small punch thru the setscrew hole and then use a drill to make a small indentation on the bbl. It's not rocket science.