Tighten barrel nut with no vise?

[56FordGuy]

....I kept waiting for 56FordGuy to post one for sale in the classifieds here, but I finally ran out of patience. :D

:lol:

I have a buddy that's been after my welding bench with two vises on it for months now. Sold the welder today, so the table may not be long after. Going to keep the vises though. :)

[TNMTBik3r]

Nothing on craigslist and I didn't see anything I liked on eBay. Going to keep watching for one to buy, not in a rush.

[tnguy]

I'm sure something could be done with some 2x4s and a couple of bolts.

[wileecoyote]

I'm sure something could be done with some 2x4s and a couple of bolts.

I have literally built hundreds of ARs, as I teach build classes and have done many myself. I would highly recommend against using any homemade jig or improvised tools for mounting a barrel. The barrel nut needs to be tightened to no less than 30 ft lbs and no more than 80 ft lbs. Your actual setting will depend on how the gas tube lines up with the cogs on the barrel nut. Most seem to take anywhere from 50-80 ft lbs for a perfect fit. That's a lot of torque to apply, and it's usually somewhat difficult for most novices to do without slipping the barrel wrench even when they use my armorers tools and a HUGE shop bench mounted to my truck frame. The applied torque often raises my 6000 lb truck bed up about 2 inches. So I don't recommend trying to do this between your knees, on the floor, with C clamps, with a rubber snake, duct tape, dremel, etc. If you don't torque the barrel correctly bad things can happen later, so just be patient until you can find or borrow the right tools to do it right. If you are ever in the Lebanon area I can help you out.

[xd shooter]

I have a vise on my work truck if ya need. I'm working in Nashville just about daily & wouldn't mind helping out. I have a upper vise block also. 

 

 

Edited September 27, 2014 by xd shooter

[McGarrett]

I'm too far away probably but you can borrow Miami Vice anytime; http://ia.media-imdb.com/images/M/MV5BMjE2MjM0ODAxOV5BMl5BanBnXkFtZTcwNjEyMjYzMQ@@._V1_SX640_SY720_.jpg

[tnguy]

I have literally built hundreds of ARs, as I teach build classes and have done many myself. I would highly recommend against using any homemade jig or improvised tools for mounting a barrel. The barrel nut needs to be tightened to no less than 30 ft lbs and no more than 80 ft lbs. Your actual setting will depend on how the gas tube lines up with the cogs on the barrel nut. Most seem to take anywhere from 50-80 ft lbs for a perfect fit. That's a lot of torque to apply, and it's usually somewhat difficult for most novices to do without slipping the barrel wrench even when they use my armorers tools and a HUGE shop bench mounted to my truck frame. The applied torque often raises my 6000 lb truck bed up about 2 inches. So I don't recommend trying to do this between your knees, on the floor, with C clamps, with a rubber snake, duct tape, dremel, etc. If you don't torque the barrel correctly bad things can happen later, so just be patient until you can find or borrow the right tools to do it right. If you are ever in the Lebanon area I can help you out.

 

I've done two barrels with the "holding the vice down on the table" technique and reliably obtained the correct torque (with adjustment needed for the alignment of the gas tube hole, of course). There's absolutely no reason a simple home-made vice wouldn't achieve what is needed. Not too impressed with the truck bed thing either. 1)Most of your truck weight is up front, 2)It's sprung weight, you're not just lifting the truck, the springs are helping. I regularly lift the front of my car that much by hand just to slip the wheel ramps up against the wheels.

 

Sorry, that probably sounds a bit pissy. Not the intention. For comparison, I often use a piece of 2*6 levered under the tow hitch to break the bead on tires and I reckon I've lifted the back-end of my vehicles around 6" in doing so. 

[TNMTBik3r]

Got it fixed today, definitely requires a vise!
30 pounds appears to have been the original torque based on the gas tube hole. I torqued it to about 45 pounds.

BTW, the Wheeler Armorer's kit is nice, I got the Master kit for $100 from Cabelas a couple weeks ago.

[wileecoyote]

I've done two barrels with the "holding the vice down on the table" technique and reliably obtained the correct torque (with adjustment needed for the alignment of the gas tube hole, of course). There's absolutely no reason a simple home-made vice wouldn't achieve what is needed. Not too impressed with the truck bed thing either. 1)Most of your truck weight is up front, 2)It's sprung weight, you're not just lifting the truck, the springs are helping. I regularly lift the front of my car that much by hand just to slip the wheel ramps up against the wheels.

 

Sorry, that probably sounds a bit pissy. Not the intention. For comparison, I often use a piece of 2*6 levered under the tow hitch to break the bead on tires and I reckon I've lifted the back-end of my vehicles around 6" in doing so. 

If you were able to get the proper torque to install a new AR barrel on a new upper, while manually holding an unbolted small or medium vise down on a flat table, you must have gotten lucky and only needed to hit the minimum 30 ft. lbs. Or maybe your vise was super heavy, or maybe your torque wrench and barrel nut wrench setup was not as accurate as you think (I would bet on the latter scenario). And you must have needed at least 2 people to pull this off, as the proper installation method requires both hands on the barrel nut wrench and torque wrench, and even then some people tend to slip and chew up the barrel nut nibs or delta-pack handguard rings.

 

When I first started building ARs, say for the first 20-30 guns, I used a small standard home shop vise but it was solidly bolted to a workbench made of 2x6 boards, which was in turn bolted to the shop wall. This worked but the vise was just barely wide enough to hold the upper receiver jig, and whenever guns needed the higher torque range you could see the 2x6 support boards bending and moving a bit.

 

Then I switched to a HUGE Wilton shop vise which weighs about 80-100 lbs. alone, and I mounted it to a 2" tubular steel hitch bar that is 2 feet long, and inserted this in my big 6,000 lb. truck with a hitch that is rated to tow up to 12,000 lbs. Even with this super heavy vise mounted in a very solid way to a very heavy object, we would still see the truck bed rise up from 1-2 inches when it was necessary to torque barrels into the higher ranges of 50-80 ft. lbs. I wasn't saying this to impress you, nor to imply that we were lifting the full weight of the truck or support system, as any fool would know that not to be the case, but thanks for pointing out the obvious. I was saying this to help others realize that the proper application of 30-80 ft. lbs. of torque with the proper tools during an AR barrel installation will most often generate a significant amount of force, such that it is not safe nor practical to do this properly without a proper vise and support method. And I certainly would not try to do it without a vise, especially when the proper tools are so easily obtained or borrowed locally.

 

I also know that there are quite a few "frankenguns" on the market which inexperienced builders threw together, often using incorrect methods and improper tools. I have worked on a number of these guns and it is not unusual to see the barrel nut unscrew by hand pressure alone, which means it was never torqued at all, and was only screwed in just enough to line up a nib for the gas tube. These guns might fire ok for a while or they might have cycling and firing issues, but obviously they are out of spec which is dangerous. So I rarely buy those frankenguns unless I am looking to part them out, and the first thing I do is to tear them down and inspect the work, replacing or rebuilding as needed. But to each his own. If you are satisfied installing barrels with a rubber band, a bath towel, and some duct tape then by all means please carry on... just let me know before you go to any range that I am visiting.  :ugh:

Edited September 30, 2014 by wileecoyote

[wileecoyote]

Got it fixed today, definitely requires a vise!
30 pounds appears to have been the original torque based on the gas tube hole. I torqued it to about 45 pounds.

BTW, the Wheeler Armorer's kit is nice, I got the Master kit for $100 from Cabelas a couple weeks ago.

Good to hear that you got it done right! I have a Wheeler's wrench somewhere, and it wasn't bad at all, but I became spoiled after using the much heavier barrel nut wrench that US Military armorers use. It is much stronger and thicker steel, with a better insert for a 1/2" torque wrench, and it rarely slips unless the installer is not watching their alignment.

[tnguy]

I don't believe I "got lucky" as I recall having to go past whatever the minimum torque was to get the hole lined up to the degree that I was concerned about over-tightening. Torque wrench inaccurate? Possible I guess but it is a beam type and has done engine heads, wheel bearing and any number of other automotive applications. It would have to be *wildly* inaccurate to be far off enough to invalidate my claim in any case. I may have had someone hold the vice. I know I got my little girl to hold it for one of my barrels but I think that was for the second one which was a little easier in any case.

 

If I had needed to take the vice down in the basement and bolt it back down to my bench to obtain the desired torque, I would have. But I didn't. And my point with the truck is that that force is all relative and just cause you moved your truck some doesn't mean much.

 

Yup, just checked. Clamped the torque wench in the vice and was able to generate 50ft-lb without even trying. 

 

Though one fact I specified wrongly, I was not so much holding the vice down as gripping the butt end of the vice in my hand and allowing the vice to torque against my forearm. This allows you to use your upper body strength to generate the torque just as you might brace yourself to apply more torque if you were working with a bolted vice.

 

In fact, that would probably be a better design for torquing than the vice, a wrench that grips the upper. If you could get the handle close to where the torque wrench is, you could apply high torques with very nice precision...

Edited October 1, 2014 by tnguy

[wileecoyote]

I don't believe I "got lucky" as I recall having to go past whatever the minimum torque was to get the hole lined up to the degree that I was concerned about over-tightening. Torque wrench inaccurate? Possible I guess but it is a beam type and has done engine heads, wheel bearing and any number of other automotive applications. It would have to be *wildly* inaccurate to be far off enough to invalidate my claim in any case. I may have had someone hold the vice. I know I got my little girl to hold it for one of my barrels but I think that was for the second one which was a little easier in any case.

 

If I had needed to take the vice down in the basement and bolt it back down to my bench to obtain the desired torque, I would have. But I didn't. And my point with the truck is that that force is all relative and just cause you moved your truck some doesn't mean much.

 

Yup, just checked. Clamped the torque wench in the vice and was able to generate 50ft-lb without even trying. 

 

Though one fact I specified wrongly, I was not so much holding the vice down as gripping the butt end of the vice in my hand and allowing the vice to torque against my forearm. This allows you to use your upper body strength to generate the torque just as you might brace yourself to apply more torque if you were working with a bolted vice.

 

In fact, that would probably be a better design for torquing than the vice, a wrench that grips the upper. If you could get the handle close to where the torque wrench is, you could apply high torques with very nice precision...

Well if I am ever in the Franklin area I would like to see how you install a barrel on an upper with 50-80 ft. lbs. of torque, using a small or medium vise that is not bolted down, and doing this all by yourself. Or better yet maybe you could post a video of you doing this. I am not saying it is impossible, and I do believe that you managed to do it twice. I am just saying that it is almost certainly a bit awkward and not so easy (especially for novice builders), and that it would not be as safe or as precise as using a proper vise that was bolted down. Even with my heavy vise mounted to the truck, I am careful to keep the torque wrench and barrel nut wrench aligned exactly right so that they will compress the weld spring and not slip out and strip the barrel nut or take chunks out of the aluminum handguard rings. I do agree with you that it doesn't require super human strength to generate 50-80 ft. lbs. of torque, as I have kids as young as 10 years old do it during my classes, but it is still a significant amount of force and in my opinion, based on hundreds of builds with all manner of guns and tools, that it is best to use a vise properly secured.

[Omega]

All I did was stand on the base with a foot on each side while torquing the barrel nut, quite easy really. But that was because my bench was still drying from when I redid the top. Much easier with a vice to be sure but it can be done.
The thing is,I wonder just how important the whole torque thing really is seeing as this system is just hand tight: https://www.coppercustom.com/shop/parts-kits/dolos-ar15-quick-change-barrel-system/

[tnguy]

Well, I don't consider myself photogenic and have no idea when I'll next be assembling an upper but sure.

[Trekbike]

Some of the new free floating hand guard systems today have gone to using a barrel nut that doesn't have to be timed with the gas tube which makes the process a breeze.   I used a Yankee Hill Machine SLR series on my TGO build and was quite happy.   

[mikegideon]

Some of the new free floating hand guard systems today have gone to using a barrel nut that doesn't have to be timed with the gas tube which makes the process a breeze.   I used a Yankee Hill Machine SLR series on my TGO build and was quite happy.   

 

My DD Lite Rails are that way. Torque it to their spec, and move on.

[TGO David]

Jonathon, your boss has a vice.  And the tools to do this.  And doesn't live too far from you.

[TNMTBik3r]

Jonathon, your boss has a vice.  And the tools to do this.  And doesn't live too far from you.

 

Yeah I know but I wasn't going to bother anyone with it. I needed a good excuse to buy a vise anyways  :)

I have one now and got everything tightened up right. Plus now I have everything to build my pistol upper without needing help (I think).