AR barrel help

[slavenoid]

I feel like this is a dumb question, but I don't know how to Google it.

So I was trying to remove a muzzle brake without the proper equipment (I know, I know) and accidentally started unthreading the barrel thinking the muzzle brake was spinning. I noticed what was happening and tightened the barrel back on. Could I have screwed anything up by doing this? I have never built an upper so I'm not too familiar with gas tubes and what not.

I'll setup a vice and proper tools before attempting again.

[fishngamereaper]

How far did you spin it
Anything beyond 1/4 inch or so you probably fubard the gas tube.
Take the handguard off and inspect it yet...?

[slavenoid]

How far did you spin it
Anything beyond 1/4 inch or so you probably fubard the gas tube.
Take the handguard off and inspect it yet...?

Not sure how much but I saw the gas tube twisted some. I didn't take it off and inspect I was hoping I wouldn't have to. I'll see what it looks like I guess.

[slavenoid]

Okay I managed to get everything apart. Turns out the gas tube is bent and the gas key is damaged so I couldn't get the bolt to go forward enough to take it apart easily. Had I thought to wiggle the gas tube it would have saved some serious time. Looks like I'm going to get my crash course in gas systems after all.

[fishngamereaper]

Nothing like learning the hard way...

Gas tubes are pretty easy
Even tho your tolerances shouldn't be off I would recommend a go no go gauge since you spun the barrel.
Make sure it's still good to go.
When your done your almost halfway to knowing how to build an AR..

[slavenoid]

So when I get everything figured out and ready to tackle the muzzle brake again does a vise and reaction rod or bev block keep me from spinning the barrel again?

[grimace]

So when I get everything figured out and ready to tackle the muzzle brake again does a vise and reaction rod or bev block keep me from spinning the barrel again?

Yes, Its best to have a reaction rod in a vice, I've done it before with a block in the mag well but it puts a lot of stress on the lower. 

G

[Alchase]

So when I get everything figured out and ready to tackle the muzzle brake again does a vise and reaction rod or bev block keep me from spinning the barrel again?

Yes, Its best to have a reaction rod in a vice, I've done it before with a block in the mag well but it puts a lot of stress on the lower. 

G

 

A reaction rod in a vice is the way to go.
Gas tubes are easy to hose up.

[lee]

Hi,

The barrel on the AR platform rifle is not threaded into the upper receiver. It indexes on a pin and then the barrel nut is screwed into the upper receiver and torqued to ~ 30ft lbs while aligning the gas tube hole. This nut holds the barrel to the receiver.  In other words, if you do spin an AR's barrel, head space should not be affected, the barrel is not unscrewing form the receiver, it's just spinning behind the nut,  just the gas tube and possibly the index pin are damaged.

YMMV,
Lee

[hunter399]

Hi,

The barrel on the AR platform rifle is not threaded into the upper receiver. It indexes on a pin and then the barrel nut is screwed into the upper receiver and torqued to ~ 30ft lbs while aligning the gas tube hole. This nut holds the barrel to the receiver.  In other words, if you do spin an AR's barrel, head space should not be affected, the barrel is not unscrewing form the receiver, it's just spinning behind the nut,  just the gas tube and possibly the index pin are damaged.

YMMV,
Lee

Lee is correct.
Barrel on an ar has no threads to screw into the receiver.
The index pin keeps barrel aligned so gas tube and feed ramps are in correct positioning.
You could have a few issues.
The index pin on the barrel could be messed up .
Threads on the upper for the barrel nut could be messed up.
The index pin on the barrel could of messed up your aluminum upper in the barrel slot.
These are all things I would look at on tear down.

[slavenoid]

I was wondering how that could even happen. Something needs checking for sure. I'll get some tools and see what I can figure out. It's my wife's deer rifle so hopefully I can get it squared away soon. I was eager to throw on my newly acquired suppressor and should have used a little more caution.

[hunter399]

Not sure where you got your upper.
But when I've bought complete uppers.
Then changed muzzle brakes and stuff.
These factorys over tighten everything,almost takes a breaker bar to get the stuff apart.
It's ridiculous.
They do that so you don't send it back for quality control issues.
Same time ,you can't get it apart.
I believe it took me an hour to get a bear crk upper muzzle break off.

[b23]

I bought a set of Wagner Industries channeled soft jaws for my vice and they work great.  They're kind of a soft-ish rubber material so they really grip the barrel well without having to seriously wrench the vice down hard on the barrel.  I have both their channeled and flat soft jaw inserts but the set with the channel in it is pretty much all I ever use.  There's magnets in the backing plate that hold them in the vice and they work great.  My AR10 has a CF Proof barrel on it and they worked great with that barrel and no slipping also.

There's other soft jaw inserts for vices that cost quite a bit less but the material is much harder.  The others may work well too but I know how the Wagner Industries soft jaws work and highly recommend them.

[slavenoid]

Not sure where you got your upper.
But when I've bought complete uppers.
Then changed muzzle brakes and stuff.
These factorys over tighten everything,almost takes a breaker bar to get the stuff apart.
It's ridiculous.
They do that so you don't send it back for quality control issues.
Same time ,you can't get it apart.
I believe it took me an hour to get a bear crk upper muzzle break off.

It's a Larue complete upper a quick Google search looks like they're usually stuck on there pretty good.

[hunter399]

There is a way to put into a vise .
You need two,1x4 blocks of wood.
You put one block where the scope goes on a flat top upper.
Other block goes over the flat bottom of the upper between the pins.
Clam in vise,with barrel sticking straight up.

Just a disclaimer here.
That's the way I did it. To build an upper. Barrel replacement or whatever. It's not the intended way. But it may get ya by.
You guys know skin the cat,turn a nail into a screw ,make lemonade all that.
It's probably better to use cedar or a really soft wood.
But I've clamped them,and had indents in the wood from the rail.
It worked in a pinch.

Ohh and I was wrong,not mag well.
It's been awhile since I built one,thanks inslee