How do you secure the lower when torquing the castle nut? - Page 1

AR-15 » Build It Yourself

AR Sponsor:

Site Notices

[ARCHIVED THREAD] - How do you secure the lower when torquing the castle nut?

Posted: 9/26/2015 9:50:47 PM EDT

I have used a magwell vice block when torquing but I didn't like all the torque on the lower. I have been clamping the receiver extension in the lower and I think this puts less stress on the lower. Is this the proper way to secure the lower?

Posted: 9/26/2015 9:54:42 PM EDT

[#1]

I'm an idiot and misread your question.

Posted: 9/26/2015 10:11:16 PM EDT

[#2]

are you tightening the buffer tube or the barrel ? i thinking the buffer tube here is a spec its only 3.33 fp but i think a little more is good to
the way your doing it is pretty common way but if ya really want it tight get soft jaws for your vise and go to town

" />

Posted: 9/26/2015 10:22:54 PM EDT

[#3]

Quote History

Quoted:
are you tightening the buffer tube or the barrel

View Quote

Buffer tube.

Posted: 9/26/2015 10:28:09 PM EDT

[#4]

soft jaws for your vise or cardboard and clamp the lower up close to the end by the thread ring .
i like your idea of the receiver tube do you have a half round blocks to grab on to so's not to crush the tube
are you having a prob with it coming loose

Posted: 9/26/2015 10:36:48 PM EDT

[#5]

I don't think you are going to hurt the lower using a mag well block. It doesn't need a lot of torque if properly staked.

I tightened mine w/ a brass drift, holding it in my lap, then staked it w/ a spring loaded center punch.

I am sure the way your doing it works fine as well.

Posted: 9/26/2015 10:38:15 PM EDT

[#6]

Between my buddies legs and his very stout arms.

Posted: 9/26/2015 11:26:53 PM EDT

[#7]

spec's only 3.33fp of torque unless your not staking it then a little more is good

Posted: 9/27/2015 12:10:00 AM EDT

[#8]

I grabbed the lower with my left hand and used the buffer lockring spanner on the nice cheap TAPCO AR tool in my right hand.

Was I supposed to clamp it in a vise? Can't see why it would be needed...

Posted: 9/27/2015 12:34:00 AM EDT

[#9]

The torque spec is 38 to 42 FOOT POUNDS and be sure to lube the threads with moly grease... This is not something you can do in your lap, a vise is required.

After the castle nut is torqued you stake the end plate in 2 places.

I use these to clamp the lower in the vise. > Link.

Posted: 9/27/2015 12:44:51 AM EDT

[#10]

Between my legs.

It's a very versatile answer.

Posted: 9/27/2015 1:59:09 PM EDT

[#11]

according to the spec sheet it's 40 inch pounds not foot pounds thats 40 / by 12 = 3.33 foot pounds but maybe the spec is wrong ?

Posted: 9/27/2015 2:20:04 PM EDT

[#12]

Quote History

Quoted:
The torque spec is 38 to 42 FOOT POUNDS and be sure to lube the threads with moly grease... This is not something you can do in your lap, a vise is required.

After the castle nut is torqued you stake the end plate in 2 places.

I use these to clamp the lower in the vise. > Link.

View Quote

I guess I need to retorque mine!

Posted: 9/27/2015 3:47:31 PM EDT

[#13]

That is a mis-print it is 38-42 ft/lbs.
Check a later version.
All of my carbine REs would be very surprised to learn that I abused them and they should have broken.
Also the buffer and BCG are designed to bottom out.
Doing otherwise is called short stroking and leads to various problems.

Posted: 9/27/2015 4:07:34 PM EDT

[#14]

Quoted:
I have used a magwell vice block when torquing but I didn't like all the torque on the lower. I have been clamping the receiver extension in the lower and I think this puts less stress on the lower. Is this the proper way to secure the lower?

View Quote

Clamping the lower is what the TM calls for.
Never the less there are people that like clamping the RE for carbine REs.

Posted: 9/27/2015 8:19:05 PM EDT

[#15]

i believe PCF and 556Cliff are very right it is 38-42 foot pounds of torque on the buffer tube castle nut that first spec is incorrect and they are right
it's a miss print at 40 inch pounds on that first spec

page 250
but in pdf reader its page 0025-8
the web page address below is the whole manual in pdf 430 something pages

www.kdeguns.com/ar-manual/M4%2016%2023Pchange8.pdf

www.kdeguns.com/ar-manual/M4%2016%2023Pchange8.pdf

this is the page below

</a>" />

thank you guys for keeping it straight
lock load live free

Posted: 9/27/2015 8:36:24 PM EDT

[#16]

Here is the Official clamping method this is for the rifle tube they don't specify for the carbine but logic would say its the same
when tighting the castle nut same forces / torques in the same places
page 0025-7

" />

Posted: 9/27/2015 8:57:38 PM EDT

[#17]

Do these stakes look alright? Sorry for the bad pics

Posted: 9/27/2015 9:41:02 PM EDT

[#18]

Quote History

Quoted:
Do these stakes look alright? Sorry for the bad pics
<a href="http://s280.photobucket.com/user/7lf10/media/FE160D24-7630-4A04-B82A-4F0B220EBD70_zpseyrpohfq.jpg.html" target="_blank">http://i280.photobucket.com/albums/kk179/7lf10/FE160D24-7630-4A04-B82A-4F0B220EBD70_zpseyrpohfq.jpg</a>
<a href="http://s280.photobucket.com/user/7lf10/media/8825D2DA-1986-4DA1-8517-0D0FDFC4DC1F_zps0o7lbqlv.jpg.html" target="_blank">http://i280.photobucket.com/albums/kk179/7lf10/8825D2DA-1986-4DA1-8517-0D0FDFC4DC1F_zps0o7lbqlv.jpg</a>

View Quote

Your stakes are fine. It just needs enough metal displaced to keep the nut from being able to easily turn.

I went to the trouble to (crudely) carve out a pair of wooden blocks to protect my lower the first time I torqued a castle nut. Since then, I have used Bessey nylon vise jaws to hold the lower, and had no issues.

The spec is 40 ±2 FOOT pounds of torque. If your copy of the TM still says "inch pounds," it's old. That was a typo that took a while for the Army to fix, and since this still comes up, it's still not fixed in the AR hobby world.

Posted: 9/28/2015 12:09:19 AM EDT

[#19]

I made these because I like making things and im special

008 by ORION HALO, on Flickr

009 by ORION HALO, on Flickr

010 by ORION HALO, on Flickr

Posted: 9/28/2015 12:51:57 AM EDT

[#20]

Quote History

Quoted:
Here is the Official clamping method this is for the rifle tube they don't specify for the carbine but logic would say its the same
when tighting the castle nut same forces / torques in the same places
page 0025-7

http://<a href=http://i963.photobucket.com/albums/ae120/50BFG/guns/buffer%20tube%20torqe%20spec%20clamp_zpshuolnpdo.jpg</a>" />

View Quote

The TMs are written for trained personnel.
Item #4 says how to clamp.
Item #5 gives rifle specs.
Starting with Item #6 it talks about carbines.
If they wanted a different clamping method it would have come after Item #5.
They could have been more clear about it, but anyone working on weapons should have been school trained and would already know the lower clamps the same for both.

Posted: 9/28/2015 1:14:07 AM EDT

[#21]

I like this from Rhine Group Firearms, fits all tubes and is $29.75, pop it in your vise and squeeze.
All the stress is on the tube and not the lower.

http://www.762sass.com/index.php?route=product/product&path=59_84&product_id=246

Posted: 9/28/2015 10:38:27 AM EDT

[#22]

Quote History

Quoted:
I made these because I like making things and im special

<a href="https://flic.kr/p/yTyGS3" target="_blank">https://farm1.staticflickr.com/691/21586938918_a2a457302b_b.jpg</a>008 by ORION HALO, on Flickr

<a href="https://flic.kr/p/yLxWpQ" target="_blank">https://farm6.staticflickr.com/5778/21507573910_3ebb2d418d_b.jpg</a>009 by ORION HALO, on Flickr

<a href="https://flic.kr/p/y7hqjF" target="_blank">https://farm6.staticflickr.com/5767/21074519163_4d705e7da1_b.jpg</a>010 by ORION HALO, on Flickr

<a href="http://s1157.photobucket.com/user/NOVESKEN4/media/2014ARRAILS026_zps42c0bf7a.jpg.html" target="_blank">http://i1157.photobucket.com/albums/p590/NOVESKEN4/2014ARRAILS026_zps42c0bf7a.jpg</a>

View Quote

Great minds think alike! I also made an internal lower receiver support block out of hard wood (Oak). Very smart guys we are... I just wish I was smart enough to figure out how to post a picture of it.

Posted: 9/29/2015 8:18:01 AM EDT

[#23]

Quote History

Quoted:
Between my buddies legs and his very stout arms.

View Quote

phrasing!

Posted: 9/29/2015 9:39:54 AM EDT

[#24]

I just use the magazine vise block. I have done this for a dozen or so lowers torquing all between 35-40 ft/lbs with no ill effects. The lowers do flex but I don't see why they shouldn't be able to take it.