Barrel Nut Rod

[TheEnigma]

As I'm still building my first Grendel, and the brown Santa hasn't delivered my barrel yet, I have a question regarding the barrel nut: is it the same dimensions as a regular 5.56 barrel nut? the reason I ask is, there is a tool much like the Geissele Reaction Rod that Brownells sells, but is $38 instead of $100.

[cory]

Did you buy a blank or a drop in barrel?

[TheEnigma]

.264 LBC barrel from BHW. Complete with barrel extension.

[explorecaves]

Both the Geissele and the brownells barrel EXTENSION tool will work the same. These are different than a barrel nut tool...

[TheEnigma]

Extension..:pwhoops! But will it work for a Grendel extension?

[explorecaves]

ar15 barrel extension is the same regardless of caliber it chambers

[Tedward]

Extension..:pwhoops! But will it work for a Grendel extension?

Yes it will work and they work well, I have that too. You might want to get this too so you can mount it in the vise, hand tighten barrel to upper. Then set it in the attached tool with the barrel pointing toward the floor. http://www.brownells.com/gunsmith-tools-...od468.aspx

Insert the tool thru the upper and lock it in the barrel extension. Torque to 30 lbs, then turn until the gas port lines up. Pretty easy with this tool, I wish I had bought one a year ago.

[TheEnigma]

Excellent info gents! Much appreciated!!

[jurassic]

As I'm still building my first Grendel, and the brown Santa hasn't delivered my barrel yet, I have a question regarding the barrel nut: is it the same dimensions as a regular 5.56 barrel nut? the reason I ask is, there is a tool much like the Geissele Reaction Rod that Brownells sells, but is $38 instead of $100.

I have the version from Geissele, the big difference is the length and the flats machined on it at one end. It allows you to clamp the rod into a vice, and it works fantastic! Expensive, but worth every penny. No receiver clamps of any kind needed.

[Tedward]

I have the version from Geissele, the big difference is the length and the flats machined on it at one end. It allows you to clamp the rod into a vice, and it works fantastic! Expensive, but worth every penny. No receiver clamps of any kind needed.

With that Geissele model, you need a barrel nut wrench to turn the barrel nut at some point. I just use the one I posted to hold it stationary for a good reason. When you use a torque wrench, it measures from the point it connects to the socket like the end of the shaft in the picture above. If you offset where you connect to the barrel nut wrench to the torque wrench, you are over torquing it. That added leverage from not being in the center of the object like the one above, you will over torque it and possibly cause failures. Even the barrel wrench I posted has a 1/2" Square hole for a socket but if you do not do your homework, it will not be accurately tourqued. Its like using a breaker bar to tighten it. Not a good idea, that is why I went with this model. 30ft. lbs. of torque is 30 ft. lbs of torque in the right place.

[explorecaves]

With that Geissele model, you need a barrel nut wrench to turn the barrel nut at some point. I just use the one I posted to hold it stationary for a good reason. When you use a torque wrench, it measures from the point it connects to the socket like the end of the shaft in the picture above. If you offset where you connect to the barrel nut wrench to the torque wrench, you are over torquing it. That added leverage from not being in the center of the object like the one above, you will over torque it and possibly cause failures. Even the barrel wrench I posted has a 1/2" Square hole for a socket but if you do not do your homework, it will not be accurately tourqued. Its like using a breaker bar to tighten it. Not a good idea, that is why I went with this model. 30ft. lbs. of torque is 30 ft. lbs of torque in the right place.

Tedward is correct on this. But there is an easy calculation one can do to account for the difference.

[haustinv]

While everyone is on the topic of correct torque I have a question. Torque specs are usually specified as dry or lubricated and if lubricated with the required lube. Does anyone know if the 30-80 ft/lb spec for the barrel nut is a dry spec or lubed spec? Also I was taught that when you torque something it is a good idea to torque and loosen 3 times before the final torquing in order to get an accurate reading. Would this apply to our AR's also?

[Buster]

Coming from an automotive mechanic background of 30+ yrs, whenever I deemed something "torque spec" critical, i.e., main bolts/rod bolts/head bolts, I would take the time to chase the bolts/holes/nuts with a corresponding tap/die with some Cyclo Break Away (50 times better than WD-40) and then clean the bolt/holes/nuts with Brakleen, which doesn't leave a film like carb cleaner does, then put the torque wrench to it.
Being fairly new to the AR build, I just make sure the threads are CLEAN on the nut and receiver and do a 30 lbs/ft, loosen, 40 lbs/ft, loosen, 50 lbs/ft final. Re-check from time to time. So far, so good...nothing has come loose......

[rasp65]

Hoss You and Buster is correct about torquing the barrel nut 3 times. AR specs call for grease to be applied to the threads.

[NugginFutz]

Hoss You and Buster is correct about torquing the barrel nut 3 times. AR specs call for grease to be applied to the threads.

Just avoid the Lithium grease. I pass this tip on from LRRPF52, who tells me that he heard it from Bill A., who says it is because the stuff rots and smells bad.

[Tedward]

Just avoid the Lithium grease. I pass this tip on from LRRPF52, who tells me that he heard it from Bill A., who says it is because the stuff rots and smells bad.

There is a product made for this. http://www.brownells.com/gunsmith-tools-...=083050100