Should the titanium barrel nut be installed so that the under-head area is acting as a bearing area against the upper receiver? Or is it purely for wrenching flats, and it just relies on torque? Are these UNJ threads? Thanks.
Seekins barrel nut question
- Thread starter Solid_Squirrel
- Start date
It's the modular upper and rail. Do you tighten the titanium barrel nut all the way down?
Ok thanks. I thought so, but I'm a noob. Here's the specs FWIW
Rainier Ultramatch 300 BLK 16" 1:8
Seekins Billet upper and 15" keymod rail
Mega GTR-3S ambi
ALG ACT
Giessele gas block
Rainier Ultramatch BCG, permapin
DD fixed BUIS w/ chevron site post
Magpul CTR w/ Battleline SAPR
Norgon ambicatch
PWS .30 FH
17-7 action spring
But first I'm going to build the Mega lower as a pistol, with a Rainier Ultramatch .223 Wylde 7.5" 1:8 twist, with a Mega billet side charging upper.
This. Get a 1 1/8" crow's foot wrench, attach to your torque wrench, and torque to specs. Glen Seekins recommends 45-50ft/lbs, no grease used.
I usually tighten twice to above 35 ft/lbs and loosen the nut, just to ensure the barrel is fully seated, then take it to 45ft/lbs for the final torque. My last Rainier barrel and iMRT-R upper was really snug on each other requiring using the barrel nut to walk the barrel into place, while the Noveske barrel and iMRT-3 upper fit like a glove.
Here's a thread with more information: http://www.snipershide.com/shooting...79849-seekins-upper-gunsmithing-question.html
Just follow directions. Don't over complicate it. If you think there's a chance you'll replace the barrel, aeroshell the threads. Seekins doesn't grease the threads on their factory barrels, but they said it can't hurt to do it if you're assembling them.
So much for "follow directions" to then just winging it any ole way you feel like winging it!
Look, I have yet to see Glen or anyone from Seekins recommend or even so much as hint that running 33MS (or any other antiseize) on the threads is advisable unlike on other barrel nuts/threads/etc. In fact, they have recommended just the opposite and recommended to NOT run any antiseize/grease/etc. because of the likelihood of over-torquing the nut which can potentially cause damage to your components. If you have some information to the contrary, then by all means share the wealth, but the specific directions from Glen et al. in many other threads on the subject (here, on BARFCOM and elsewhere), including the one in response to my own questions last year was:
Oiled threaded will have a different torque rating or you will over tighten. Follow the directions given from the MFG.
"Most times, the specified torque value assumes clean and dry parts. Clean means no dirt, rust, dried-up *gasket sealer or anything except shiny metal. Wire-brushing the threads will help remove rust or sealant. Engine fasteners, like head bolts or main cap bolts, are often specified to be torqued with 30-weight engine oil wetting the threads and washer. If you're installing a fastener that has a dry torque spec, and the threads and bolt face are oiled, you'll need to reduce the torque by 15 to 25 percent, because the slipperier surfaces will decrease friction. Teflon-bearing lubes or moly-sulfide engine assembly lubes can reduce friction enough to require a 50 percent reduction in tightening torque. Even casually substituting a zinc- or cad-plated bolt or washer for an unplated one calls for, respectively, a 15 or 25 percent reduction in applied torque, because the plating acts as a lubricant. Fail to heed this advice and the fastener will be seriously overtightened. You'll either snap it or crush a gasket to the point where it leaks. "
Just a little excerpt from an article about this relating to cars, same goes with guns or anything else
"Most times, the specified torque value assumes clean and dry parts. Clean means no dirt, rust, dried-up *gasket sealer or anything except shiny metal. Wire-brushing the threads will help remove rust or sealant. Engine fasteners, like head bolts or main cap bolts, are often specified to be torqued with 30-weight engine oil wetting the threads and washer. If you're installing a fastener that has a dry torque spec, and the threads and bolt face are oiled, you'll need to reduce the torque by 15 to 25 percent, because the slipperier surfaces will decrease friction. Teflon-bearing lubes or moly-sulfide engine assembly lubes can reduce friction enough to require a 50 percent reduction in tightening torque. Even casually substituting a zinc- or cad-plated bolt or washer for an unplated one calls for, respectively, a 15 or 25 percent reduction in applied torque, because the plating acts as a lubricant. Fail to heed this advice and the fastener will be seriously overtightened. You'll either snap it or crush a gasket to the point where it leaks. "
Just a little excerpt from an article about this relating to cars, same goes with guns or anything else
This. Only difference is I always put white lithium grease on the barrel extension and barrel nut threads.
There is ALOT of leeway as far as torque goes. Around 50ft lb will be just fine.
This is the cheapass crows foot I used and worked great.
Sunex 97736 1/2-Inch Drive 1-1/8-Inch Jumbo Crowfoot Wrench - Amazon.com
I ended up getting a gently used Snap-On crowfoot for $20 off E-Blech. I used this with my 20-120lbs TechWrench and Geiselle reaction rod.
So much for "follow directions" to then just winging it any ole way you feel like winging it!
Look, I have yet to see Glen or anyone from Seekins recommend or even so much as hint that running 33MS (or any other antiseize) on the threads is advisable unlike on other barrel nuts/threads/etc. In fact, they have recommended just the opposite and recommended to NOT run any antiseize/grease/etc. because of the likelihood of over-torquing the nut which can potentially cause damage to your components. If you have some information to the contrary, then by all means share the wealth, but the specific directions from Glen et al. in many other threads on the subject (here, on BARFCOM and elsewhere), including the one in response to my own questions last year was:
Says you can use whatever you want. Definitely doesn't say not to use any, and since I never keep anything the way it started, I greased, and it's perfect.
https://www.ar15.com/archive/topic.html?b=2&f=438&t=241957
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Hadn't seen that thread/reply from Matt before just now. I was basing my own procedures and comments on info I've received and otherwise read direct from Glen.
So what, pray tell, did you torque your barrel nut down to with the addition of the 33MS since the Seekins 45-50ft/lbs is based on a dry torque value?
Did you reduce your torque value accordingly or did you, again, just wing it as I stated before?
And if lubed, I'd concur that a lower target/indicated torque should be used (because of friction).
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