Barrel Nut / Torque Wrench

[cmacclel]

we are talking about aluminum on steel (OE style nut), and as far as using a torque wrench I think it is foolish not to use on on everything but this is just my opinion,

Bushmaster had this problem years back where the locator pins were bending throwing the barrel/sight alignment off from over torquing of the barrel, This came right from a bushmaster employee while I was there visiting the plant in windham years ago, besides why take the chance? 40Ftlbs to you may only feel like 10ftlbs to someone else! also we are talking about a fine thread aluminum with a fairly thin wall and a rather large nut, the last thing I would want to do is rip the threads off my upper or tighten it to the point it galls, don't be anxious and just do the right thing, they put a spec on it for a reason...

also the barrel nut threads Should be lubricated, the recommended lubricant suggested by Colt is Aeroshell 33MS, but I would think any medium bodied lube would be fine

18 TPI is hardly a fine thread

I can't understand how over torquing a barrel could bent the locator pin.....not saying it didn't happen....... just makes no sense to me unless the Bushmaster employee added a zero to the torque specs and then I would think you would rip the threads off of the upper rather than bend a hardened steel pin

 

[PatMcD]

Don't overthink this.
You tighten it till the nut is snug. Now you want to go to the next gas tube hole. To get there, you will be using 40-80lbs of torque whether you use a torque wrench or not.
If you don't go far enough to the correct gas tube hole, you'll be able to move the nut by hand. The correct hole will require effort. There is no way to get to the next hole beyond the correct one.

Oh, and a cut-off section of gas tube fitted in the bolt carrier is the best thing to check alignment.


And how would the locater pin bend on the Bushmaster barrels? The barrel itself is a slip-fit. It's not like a M1 barrel.

 

[sschevy]

18 TPI is hardly a fine thread

I can't understand how over torquing a barrel could bent the locator pin.....not saying it didn't happen....... just makes no sense to me unless the Bushmaster employee added a zero to the torque specs and then I would think you would rip the threads off of the upper rather than bend a hardened steel pin

Ok for you my friend, that knows more than the people that actually build these, Is a direct quote from bushmaster...(and I have it in print in the catalog from 1998 if you need to see it)

And I quote:

Q: I have just installed a new upper receiver on my old barrel, and now my rifle shoots way to one side. I can adjust for the windage, but what happened here? Is my barrel no good?

A: This is a problem that took us some time to figure out but it is so simple, we're kicking ourselves. The little index pin that lines up the upper and lower is very soft, so that it can shear off if the barrel is over-torque. This is to prevent damage to the receiver when barreling. This pin will distort slightly before it snaps, and this slight distortion is enough to create the excessive windage you describe. A new pin costs only $1.50 and removing the old pin is as easy as grabbing onto it with vise grips and twisting it up and out. Drive a new one in and try the upper on. The pin may shear when you try to remove it, but they are easy to drill out. Just be sure not to drill into the barrel extension. A new pin will be like having a brand new barrel (as far as the receiver is concerned, it is new) and that windage problem should disappear.

While I am at it, the barrel nut I believe is 1 3/16 so TPI of 18 would be fine thread, being the standard TPI range of this size goes from 8,12, 16,18,20....18 and 20 being classified as "UNEF"...that would mean "unified national Extra fine" if you did not know that....I knew there was reason your dad always called you "rocket scientist"


Do a search on it ...dozens of people are complaining about the windage problems with Bushmasters, they have been for years...Now that they are no longer "Bushmaster" so to say, I do not know if the problem is on going, But I have read of people having the same problem with BCM uppers now.....

Oh and for the record I am not picking on Bushmaster I have owned 4 Bushmasters and not one of them had windage problems.

Your barrel cutting and threading is second to none I'll give you that, but you really have to stop using that pipe wrench and 3 foot extension bar to put the barrels back on! I'll be by after work to check out the new toy Andy told me about

 

[sschevy]

I use torque extensions on my torque wrenches quite a bit and find this site very handy its interactive... just punch in you lengths and desired torque and it does all the work for you.... if anyone is interested

http://www.belknaptools.com/support-library/extensions-calculator/

 

[jasons]

Q: I have just installed a new upper receiver on my old barrel, and now my rifle shoots way to one side. I can adjust for the windage, but what happened here? Is my barrel no good?

A: This is a problem that took us some time to figure out but it is so simple, we're kicking ourselves. The little index pin that lines up the upper and lower is very soft, so that it can shear off if the barrel is over-torque. This is to prevent damage to the receiver when barreling. This pin will distort slightly before it snaps, and this slight distortion is enough to create the excessive windage you describe. A new pin costs only $1.50 and removing the old pin is as easy as grabbing onto it with vise grips and twisting it up and out. Drive a new one in and try the upper on. The pin may shear when you try to remove it, but they are easy to drill out. Just be sure not to drill into the barrel extension. A new pin will be like having a brand new barrel (as far as the receiver is concerned, it is new) and that windage problem should disappear.

Perfect example of why Bushmaster uppers suck.

First of all the index pin doesn't "line up the upper and lower." It simply makes sure that the barrel is installed right side up in relation to the upper. It has nothing at all to do with the lower.

Secondly that index pin should be under little or no lateral pressure if installed properly. The barrel nut doesn't even touch the index pin. If you can shear that pin you're somehow putting like 8000 foot pounds of lateral torque on it (how I don't know,) or the hole was drilled too far back and it's hitting the receiver before the extension is seated all the way into the upper.

Third, if they're seriously recommending then end-users whip out a drill to fix windage tracking problems that Bushmaster caused due to improper assembly they're f-ing insane.

A new pin will be like having a brand new barrel (as far as the receiver is concerned, it is new) and that windage problem should disappear.

Oh cool, I don't need to re-barrel after a season of high-power shooting anymore. I can just replace the index pin on my barrel extension.

 

[cmacclel]

If you do a search on "Bushmaster Canted Front Sight" you will see many threads some that are fairly new within the past year. So I guess there still over torque there barrels? If thats the case then you mean to say that no one on the planet has over torqued another MFG upper and barrel and bent there pin I think that was Bushmasters "easy excuse" for apparently bad Quality Control. One person said he sent his rifle back and they just smashed his front site with a hammer to line the sights back up I guess 16 clicks of in windage is "Mil-Spec".

Anything is possible......if they clamped the barrel in a vise to torque the barrel nut I could see this bent sheared pin issue happening but not if it was done properly with the upper clamped down.

Mac

 

[jasons]

If you do a search on "Bushmaster Canted Front Sight" you will see many threads some that are fairly new within the past year. So I guess there still over torque there barrels? If thats the case then you mean to say that no one on the planet has over torqued another MFG upper and barrel and bent there pin I think that was Bushmasters "easy excuse" for appently bad Quality Control. One person said he sent his rifle back and they just smashed his front site with a hammer to line the sights back up

Anything is possible......if they clamped the barrel in a vise to torque the barrel nut I could see this bent sheared pin issue happening but not if it was done properly with the upper clamped down.

Mac

I don't know. Canted front sight bases could just have the taper pins drilled improperly, which seems a lot more likely to me.

 

[Gammon]

Well Said.

Don't overthink this.
You tighten it till the nut is snug. Now you want to go to the next gas tube hole. To get there, you will be using 40-80lbs of torque whether you use a torque wrench or not.
If you don't go far enough to the correct gas tube hole, you'll be able to move the nut by hand. The correct hole will require effort. There is no way to get to the next hole beyond the correct one.

Oh, and a cut-off section of gas tube fitted in the bolt carrier is the best thing to check alignment.


And how would the locater pin bend on the Bushmaster barrels? The barrel itself is a slip-fit. It's not like a M1 barrel.

 

[sschevy]

Hold on I have to go put my boots on to get through this S***. The pin tells you what side of the barrel is up?? If you can not tell which side is up from the other factors of the barrel you should not even be allowed to own a wrench never mind a firearm. There are many other factors that make it apparent which side is up....and as far as bushmasters go.....they are not bad rifles...but all I own are colts now..

The simple fact that I was actually there at the factory and saw this problem is not enough proof I guess.

Proof positive that you actually can't read if you think they are suggesting to drill to fix a windage problem...read it again they are simply stating that if your pin shears off that the PIN is easily drilled out...

Once again the moral of this thread is to NEVER give you opinion on NES even if you have the experience of seeing it happen backing you up!

 

[jasons]

Hold on I have to go put my boots on to get through this S***. The pin tells you what side of the barrel is up?? If you can not tell which side is up from the other factors of the barrel you should not even be allowed to own a wrench never mind a firearm. There are many other factors that make it apparent which side is up....and as far as bushmasters go.....they are not bad rifles...but all I own are colts now..

The simple fact that I was actually there at the factory and saw this problem is not enough proof I guess.

Proof positive that you actually can't read if you think they are suggesting to drill to fix a windage problem...read it again they are simply stating that if your pin shears off that the PIN is easily drilled out...

Once again the moral of this thread is to NEVER give you opinion on NES even if you have the experience of seeing it happen backing you up!

I'm not saying that Bushmaster doesn't booger up the assembly of their rifles. They're well known for being crap. I'm just saying that if you somehow put enough torque on a barrel nut to bend or shear off the index pin then someone is doing something VERY wrong. But whatever, I'm sure Bushmaster is wicked awesome and stuff.

 

[sschevy]

I'm not saying that Bushmaster doesn't booger up the assembly of their rifles. They're well known for being crap. I'm just saying that if you somehow put enough torque on a barrel nut to bend or shear off the index pin then someone is doing something VERY wrong. But whatever, I'm sure Bushmaster is wicked awesome and stuff.

I personally would not own another Bushmaster or a DPMS for that fact...so I would not know if they were "wicked awesome" or not...out of the 4 that I owned in the mid 90's I never had a problem they all shot fine and the fit and finish was exceptional, but If a manufacturer can not go as far as proof testing or MP testing critical parts then I don't want anything to do with them..this is why I will stick with my colts and LMT's..

 

[cmacclel]

Ok for you my friend, that knows more than the people that actually build these,

Now this funny. Where talking about a company that apparently shipped many rifles with piss poor Quality Control, over tightened barrels for many years causing bent / sheared pins and canted front sights. Then Yes I would say I know more than them

What I don't underdstand is the fact they knew about this in 1998 yet without digging I see threads about canted front sites started in 2008. So knew about this for 10 years without doing anything??

Mac

 

[sschevy]

Now this funny. Where talking about a company that apparently shipped many rifles with piss poor Quality Control, over tightened barrels for many years causing bent / sheared pins and canted front sights. Then Yes I would say I know more than them

Mac

What did you just wake up? Any company can and will go through "growing pains" so to say...are you perfect? Is your product perfect? would it be "perfect" if you made thousands of them a month and not the 10 per month you make now? The answer is NO

When my shop is slow and we can do everything just right the product is very very good...perfect.... most likely not...But on days like today when I have orders totaling 600+ pieces and they need to ship Tuesday... then the possibility of shit slipping through the cracks is there as it is with any company....except in you perfect little world of OCD of course....I know things about you... don't go there

Also these companys have people working for them now that are considered unskilled workers just to keep up with the demand. the lack of skilled workers in this country is a growing problem, It is very difficult to keep track of that many people at one time and mistakes happen, high employee turnover is another problem and without actually sighting in the weapon you would not know it was canted..sighting in every single weapon would be a huge cost in a demanding competitive market. Out of thousands of weapons produced a few getting through with canted sights is like pissing in the ocean...you have to remember they are in this for the money not the love...its a business and the goal is to create cash flow...again no one is perfect...anything that you make I can find something that is not to my liking...does that make you product bad? No... but it will never be perfection for everyone

 

[sschevy]

Now this funny. Where talking about a company that apparently shipped many rifles with piss poor Quality Control, over tightened barrels for many years causing bent / sheared pins and canted front sights. Then Yes I would say I know more than them

What I don't underdstand is the fact they knew about this in 1998 yet without digging I see threads about canted front sites started in 2008. So knew about this for 10 years without doing anything??

Mac

No what is really funny is that I just did a Google search on your name with problems after it and there seems to be plenty of "threads" on problems you have with your product too! I guess we are not all that prefect are we

I have to do some work now...I will come by tonight

Kharrison...I have all the tools to complete you build if you need them my offer still stands to borrow them if you like, or come by and we can do it here...

have a good new years weekend everyone!!

 

[Colt Delta Elite]

I use a torque wrench for everthing. For an AR you do not need one....unless you personally would like to know what your torque value was. Have you ever built an AR??

Yes I have built three. The question is if you don't use a torque wrench how do you know if you went over 80 ft/lbs? The answer is you don't know.

 

[sschevy]

Yes I have built three. The question is if you don't use a torque wrench how do you know if you went over 80 ft/lbs? The answer is you don't know.

Thank you... exactly the point I was trying to make...you just worded it better.....If the torque value was not an issue there would not be one

 

[Colt Delta Elite]

Hmm which brand would this be? I have built a few AR's and cut down a bunch of barrels for people and have yet to come across a barrel nut without a gas tube hole.

Mac

I guess you've never built a 9mm then.

 

[jasons]

Yes I have built three. The question is if you don't use a torque wrench how do you know if you went over 80 ft/lbs? The answer is you don't know.

You won't be if you line up the first gas tube hole after the nut is snug. It's just not mechanically possible. (Now if you try to go past the first hole and onto the second or third like our friends at Bushmaster then all bets are off.)

If you want to use a torque wrench it's fine, but once you do a bunch of them you'll see what everyone is talking about.

 

[Colt Delta Elite]

Thank you... exactly the point I was trying to make...you just worded it better.....If the torque value was not an issue there would not be one

My only worry is going OVER the max torque.

 

[cmacclel]

No what is really funny is that I just did a Google search on your name with problems after it and there seems to be plenty of "threads" on problems you have with your product too! I guess we are not all that prefect are we

Now where getting a little off-topic......Yes every company has issues and growing pains but same issue is going on for 10 years there is *no* excuse. As for anything that I build I can assure you any problems that arise have nothing to do with quality.....wait times.....order delays yes, but ZERO quality issues.

Also you must have a different version of Google than everyone else as I cannot replicate your search for the life of me.

My only worry is going OVER the max torque.

Good point

 

[sschevy]

Now where getting a little off-topic......Yes every company has issues and growing pains but same issue is going on for 10 years there is *no* excuse. As for anything that I build I can assure you any problems that arise have nothing to do with quality.....wait times.....order delays yes, but ZERO quality issues.

Also you must have a different version of Google than everyone else as I cannot replicate your search for the life of me.




Yup

way off topic at this point....I'm finished and moving on

 

[Rob Boudrie]

Third, if they're seriously recommending then end-users whip out a drill to fix windage tracking problems that Bushmaster caused due to improper assembly they're f-ing insane.

Yeah, but they did say to be careful not to drill into the barrel extension

The pin tells you what side of the barrel is up??

Yeah - without that pin, there would be lots of AR's out there with the M4 feed ramps on the top of the chamber.

 

[jasons]

Yeah - without that pin, there would be lots of AR's out there with the M4 feed ramps on the top of the chamber.

Maybe not ~that~ bad, but even it it was off just a couple degrees accuracy would suffer.

 

[PatMcD]

Yeah, but they did say to be careful not to drill into the barrel extension



Yeah - without that pin, there would be lots of AR's out there with the M4 feed ramps on the top of the chamber.

Nevr underestimate the stupidity of the average gun owner.