Post by: slavenoid on September 24, 2023, 10:17:39 AM
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.
Post by: fishngamereaper on September 24, 2023, 10:28:01 AM
Anything beyond 1/4 inch or so you probably fubard the gas tube.
Take the handguard off and inspect it yet...?
Post by: slavenoid on September 24, 2023, 11:56:12 AM
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.
Post by: slavenoid on September 24, 2023, 01:49:10 PM
Post by: fishngamereaper on September 24, 2023, 02:18:10 PM
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.. :tup:
Post by: slavenoid on September 24, 2023, 03:16:51 PM
Post by: grimace on September 24, 2023, 03:36:05 PM
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
Post by: Alchase on September 24, 2023, 06:20:16 PM
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
:yeah:
A reaction rod in a vice is the way to go.
Gas tubes are easy to hose up.
Post by: lee on September 25, 2023, 07:03:43 AM
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
Post by: hunter399 on September 25, 2023, 10:20:02 AM
Hi,Lee is correct.
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
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.
Post by: slavenoid on September 25, 2023, 06:25:52 PM
Post by: hunter399 on September 25, 2023, 06:40:57 PM
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.
Post by: b23 on September 25, 2023, 07:54:36 PM
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.
Post by: slavenoid on September 25, 2023, 08:16:43 PM
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.
Post by: hunter399 on September 25, 2023, 08:21:12 PM
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
Post by: slavenoid on October 01, 2023, 02:58:38 PM
Post by: hunter399 on October 01, 2023, 04:10:36 PM
Managed to build a contraption on the kitchen table to hold my vise. Got the muzzle brake off finally, but I could not get the gas block off. Even heating it with a torch I snapped two allen wrenches trying to get that off. Larue doesn't want that block or tube going anywhere I guess so I worked around it. Castle nut off and the barrel detent was right where it should be. Still not sure how the barrel spun. I put it back together with a little tweaking of the bent gas tube and fired a couple rounds everything works. A real round about way of putting a suppressor on.Glad to hear ,you got it shooting again, without to much damage.
Ya ,I'm not sure why these companies put it on so tight.
Like said ,it took me about an hour to get a muzzle brake off from bear crk. I was just taking it apart so I could duracoat the stainless barrel. Cause I didn't like it being so shiny in the deer woods.
Bear crk doesn't use crush washer or nothing,just torque it till the threads are a quarter turn from stripping and call it a day.
Post by: Crown50 on October 21, 2023, 02:56:44 PM
Post by: jaymark6655 on October 24, 2023, 02:57:01 AM
You where probably turning the barrel in the barrel extension, If so you should have it reinstalled and head spaced by a gunsmith
Yeah, that thing should be torqued to 150 ft-lbs, can't imagine spinning one lose and not damaging that locator pin or the upper receiver. If that pin was still located in the notch, then its the only way the barrel could turn.