Would you use a 3/8ths or 1/2" torque wrench? I was going to take it to someone who could snug up the buffer tube stake the castle nut. It's literally a ten minute job. Some guy in the Gwinnett area quoted me $70. Multiply that by four weapons and that works out to $280 an hour. My career path is obvious.Torque spec for the castle nut is 38-42 foot/pounds. Set your wrench to 40ft/lbs and you’ll be fine, even if the wrench is off a little one way or the other.
I use a mix of Tekton and Snap-On foot/pound torque wrenches, and I use the Tekton the most.
I recommend a torque wrench because one person’s “snug” and another’s can be wildly different. I’ve had parts that folks put on “snugly” that I ended up having to apply Kroil and heat, and even cut off, to remove.
Get a wrench an do it correctly, or take it to someone that can.