The longer ar barrel wrench shows the torque wrench at a 45 degree angle to get proper torque due to length of tool. What about the short GI type tool, since it is nowhere near the length of the longer tool, doe the torque wrench go straight with the tool, or also at a 45 degree angle?

Torque wrench should be 90 degrees to neutralize the length of the tool.

As far as a shorter tool, given the barrel nut torque range, I would just set the torque wrench on the lower side of the range, and torque it.  Could also drop the tool dimensions into a basic calculator to determine where to set the torque wrench to achieve a specific torque value with an increased lever arm, if you're picky.<br abp="788">

I have done so many of them over the years and the range is quite flexible, I don't normally ever use a torque wrench anymore..

You’re way overthinking this, and making it way more complex than it is.

Torque specs for AR barrel nuts are based on the Army Technical Manual for the M16 family of weapons.  In that TM, the barrel nut wrench is used IN LINE WITH the torque wrench.

The TM procedure is built to avoid the armorer doing any math.  Put the barrel nut wrench on the torque wrench, look for a value between the numbers stated, and you’re done.

You are not applying “30-80 ft/lb of torque” TO the barrel nut.  You are applying a slightly different value to the nut, but torque to INDICATE “30-80 ft/lb of torque” on the in line torque wrench.

If you do the math, the difference between having the barrel nut wrench at 90 degrees, 45 degrees, or in line with the torque wrench is very small.  You’re not building a space station, you’re just doing a very simple armorer job.  Keep it simple...

Can we make this an automated response for when this question comes up?

Why would we, we get far more "What barrel grease should I use" questions, some weeks it is two or three times a week.

I think each of those questions needs a single day they’re allowed.  Tuesday for barrel nut grease, Wednesday for how to use a barrel nut wrench.  

In all seriousness, I think it’s way too common for people to just skip over perusing the TM.  That could explain why they overcomplicate these processes.