Tight upper AR receivers?

[Dolomite_supafly]

So I am starting another build. I bought an upper that turns out is VERY loose in the barrel channel. It is as least .007" too large so the barrel basically wobbles inside the receiver, not very good for accuracy. Barrel is good but the receiver is loose.

Anyone know of any, or had any problems, with an upper receiver being too tight? I am looking for one that is as tight as possible because this is going to be built as accurately as possible. I haven't built an AR in at least 6 years so have no idea what is good or not good as far as components any more.

Prefer forged over billet because of weight. 

[Mr.Mildot]

Never mind, I had an idea but no...that's not it...

 

 

 

Edited February 28, 2018 by Mr.Mildot

[Garufa]

Short of getting a new upper receiver, and I’m really getting creative here, couldn’t you wrap some foil tape around the barrel extension?

[Dolomite_supafly]

Not going to hack job an expensive barrel into an expensive upper receiver. 

 

[Mr.Mildot]

Have you tightened the bbl nut to spec?  Shouldn't wobble after that...and accuracy should be fine.

[Dolomite_supafly]

I've built enough ARs to understand what it takes to build a decent gun.

[MacGyver]

The CMT uppers I’ve built have required cooling to get barrels in the receiver.  On my .308, I think it would take a signed note from Congress to get it back out.  

[MacGyver]

I wonder if you could reach out to a smaller manufacturer to get them to undersize the receiver so that you need to chuck it up in the lathe and hone it to fit.  

[Dolomite_supafly]

I just need one that is in spec. The barrel extension is perfect, the upper isn't even close. Upper is also extremely tight in the charging handle channel.

[Ronald_55]

Not sure how many places local to you carry stripped uppers. But could you stop by and try some for fit?

[Dolomite_supafly]

I might have to buy a standard upper locally them machine it down to the lightweight I bought.

[martin5]

Sent you a PM. 

[MacGyver]

Will DSA not exchange it?  Seems like you could mic it and send a picture and they ought to replace it.  

Better than getting sued later on because an out of spec receiver injured someone.  

[Tooreal]

That doesn’t surprise me these days, with prices For parts So Low. It may have come from a Run of 2nds that didn’t meet Specs and were sold to make a Higher Profit? You never know?

Cant you ship it back for a refund, or for one that’s in Spec? Good Luck and I Hope it turns out to be an easy solution. 

Could you Turn Down the Front of the Receiver and get it square on the Front Face So the Barrel would fit Flush against the face and the Barrel Nut would Snug against the shoulder?

Good Luck   

 

[ballz71]

I used a Aero precision upper in one of my builds. I had to tap the barrel in with a rubber mallet. Aero also is a OEM suppler for alot of big name company now. 

[mike_f]

In the past couple of years I've bought a 4 of Aero Precision and 2 Mega stripped forged uppers. 

 

The Areo uppers were one snug, one loose, and two slightly loose with 4 different barrels. 

 

Both Mega uppers were snug.  I bought the Megas based on recommendations on the 68Forum from Harrison at AR Performance (and others too).  Mega was recently bought by Zev (the $2,000 Glock people), so they're now sold as Zev uppers. Unfortunately, it also looks like they're charging Zev-level prices for them now.

[Dolomite_supafly]

I picked up a stripped RRA upper, all is well. Just need to square it up before I begin putting it together. 

[mikegideon]

1 hour ago, Dolomite_supafly said:

Just need to square it up before I begin putting it together. 

Yes! I have had GREAT luck with that. 

[1fast4by]

I’ve used multiple Aero uppers and always had success, BCM also.... 

[ken_mays]

I've heard of people Cerakoting the barrel extension and using Loctite or Rocksett to fill in the rest of the space.   A lot of AR-10 builders need to do it because apparently there can be a big variation in dimensions between manufacturers.

 

I think in your case, it was a smart move to just use a different upper... .007" is a lot.