Personally, I think the torque value is meaningless so long as you're consistent, though hand-tight's asking for trouble IMO.
I mostly agree with you here.
We recommend 75ftlbs because it has shown a few things in testing.
If you're under about 35ftlbs the rifles sometimes have wandering zero issues. Some more torque fixes this.
Anything over 50ftlbs has never shown a wandering zero for me in my rifles or any of the testing I did.
Based on 50ftlbs I did a test where I asked several customers to install the barrel to 50 ftlbs and didn't give them a torque wrench, I used a torque transducer that I had from an old engineering project and recorded values. What we found was that the same person would be pretty consistent on 5 attempts in a row, quick succession. If I had a guy put it on and then we talked, had a coffee, did some other stuff for a few mins, then came back it was not repeatable.
Even when repeatable the torque values were all over though. Even for myself and I put barrels on and off a dozen times a day easily.
If I told them 75 ftlbs then the torque values could still range all over the place but we didn't tend to get light torques that were in the 30ftlb range. Since we know that 35ftlbs still has the tendency for a wandering zero then I needed a way to get away from that... easy, suggest a little more torque.
At 75ftlb the tendency was to be somewhere from 50-65 but typically not over 85ftlb and never over 100.
I did this because not everyone has a torque wrench and many times there's no record or even an idea of when it was last calibrated. Who knows what you're getting.
Since we've successfully tested past 125ftlb without issue on a lubricated joint then that's where the spec comes from.
On the lubrication:
Use either flavor antiseize, doesn't matter. Or you can use the Lubriplate M14 Grease that Brownells sells.
We've switched to that for a while now because it doesn't stain up cerakote like antiseize will if you get 4 molecules of it on a freshly paitned surface. Seriously, antiseize is awesome until you have to wipe it away and not leave a mark on a brand new rifle. Then it's impossible to get clean.
For the amount, use more if you're in doubt. We've had more than a few barrels come in galled to receivers over the last 5 years. None of them had too much lubricant on them, in fact quite the opposite.
