I did some searchin and did not see anything recent on this.
I am aboutto build my new lower and I have always torqued the castle nut to a little over 40in/lb then staked it. I know the new manuals say 38-40ft/lbs but honestly that has always seemed like a huge amount for aluminum threads.
So what is the suggesting torquing spec now days? Still a little past hand tight or have opinions changed and should I go for the all out 40ft/lbs.
I just use “common sense” torque value. The castle nut does NOT move much past hand tight… so give it a little snug up and stake it.
AFAIK it’s always been 40 ft-lbs. Your upper receiver can take up to 80 ft-lbs on aluminum threads, so 40 on the receiver extension is a non-issue.
Torque it to spec and restake it, my 2 cents.
The manual says 38-40 ft./lbs. I use common sense torque. I also work the threads a little and use anti-seize or grease.
I don’t see how you came to the conclusion that its too much for aluminum threads when the barrel nut is torqued 30-80ft./lbs. on the aluminum receiver.
The one time I removed a RE that was actually torqued to 40ft/lbs the threads were all chewed up, the company sent me a replacement RE and said it happens from time to time due to the torque.
IME it happens when people don’t know how to install them. I have probably done close to a thousand over my lifetime and that was almost always the case.
If your tightining it to 40 in lb? Isnt that about 3 ft lbs? thats not enough for sure.
I have always done about hand tight then just a bit more and staked it.
The only time I have ever damaged a RE was when removing an A5. Completely operator error.
I torque to 40 ft/lbs anytime I build a lower. Grease and stake as well.
It has never been 40 in/lb or just past hand tight. Unfortunately the 1991 Army / Air Force TM mil manual had the incorrect printing of the torque spec at 40 in/lb which is 3.3lbs and the reason many people had issues with extensions coming loose even when staked. Hell even Brownells had this wrong torque spec on their AR build video series which is probably still wrong and being referenced. The correct spec has always been the spec which Colt has quoted since day 1. It took 17 years to fix it, but the torque spec has been updated in the more recent 2008 Army mil TM manuals. Unfortunately the misinformation was out there for a long long time before being corrected.
Is AeroShell 33MS beneficial on RE threads?
Any time you run a steel nut on aluminum, lube is beneficial.
+1 Should you ever dunk it in water it will keep it from corroding together as well.
What…get it wet? Next thing you’re going to suggest sticking it in a pile of mud and run over it with your F150.
Not sure our hot-running delicate shooting devices can handle such abuse - according to most experts one needs an AK for that.