It never occurred to me that one can tighten the castle nut too much, but I guess you can tighten anything too much, but its not like I used a 4' pipe as a lever.
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It never occurred to me that one can tighten the castle nut too much, but I guess you can tighten anything too much, but its not like I used a 4' pipe as a lever.
you can certainly tighten it too much. Steel threading into aluminum is usually a recipe for galling if you over tighten. Moly grease or some sort of anti-seize compound CAN save you from galling the threads. Your best bet is to stick with specified torque or good and snug, then properly stake in two places. No need for blue-star torque on these things.
I was installing a rifle extension and looked in the manual to see how tight to go. Just out of curiosity, I checked the carbine specs and thought 40 +/- 2 in-lbs seemed a little loose. You can just about do that by hand with no wrench.
I have never used Moly, has anyone run into trouble with not using on the threads?
Specs from the Colt classes I've taken;
35-39 ft-lbs (Fixed Stock)
38-42 ft-lbs (Sliding Stock)
40 ft lbs is alot of torque.
Think about this people. You have a lever that is 1 foot long with a 45 pound plate hanging off of it. This is alot of torque for such small aluminum parts.
This is the torque that lug nuts are put on vehicles.
You just need to tighten this snuggly and stake it be be done with it.
I don't consider torque specs to be very valuable.
I don't torque barrel nuts to a specific spec. I hand tighten them and align the next notch on the barrel nut via the wrench. This is tight enough. You cannot torque to a specific spec on the barrel nut because it has to stop at a discrete position unlike standard fasteners.
I'm just posting what Colt recommends.
I emailed Ken Elmore of Specialized Armament and here is what he emailed back.
I use 35 ft/lbs, fixed stock, and 40 ft/lbs, sliding stock.
The only INCH / pound spec on the M16 is the carrier key.
Hope this helps.
Run-N-Gun,
Ken
Ken Elmore
Specialized Armament (1990 - Present)
Instructor, COLT Defense (1997 - 2007)
Sergeant, US Army (1986 - 1990)