Quoted:
There is a lip on all rifle buffer tubes. Carbine tubes have a nut.
This lip is machined into the tube and not adjustable.
You push the buffer retainer and spring down and screw the tube in till it stops against the lip. Tighten it just like a bolt or screw 35 foot lbs. You want to get the tube tight and not let it be loose. If the buffer retainer binds on the tube the only option to adjust is to grind a bit of metal off the tube in the area that is binding. Rifle tubes probably never need this done. I have never seen it myself.
Excellent, thanks for the explanation ekg98. I've never looked at a rifle buffer tube off a lower before so I never noticed the lip.
So how important is it to get exactly 35-39 ft-lbs of torque? I don't have a torque wrench. From the posts above it seems like most just use a crescent wrench and don't actually measure the torque. I have no concept of the amount of force required to torque to 35-39 ft-lbs with a wrench. Would this be comparable to the amount of energy you exert to curl a 35lb dumbbell (trying to come up with an analogy, that's the best I could think of)?
Is it worse to over or under torque if I'm going by hand without a torque wrench? Or do I really need to get the torque wrench?
Thanks