Re: What's involved in an AR barrel change?
A torque wrench isn't always necessary. There is a wide torque range at 32-80 ftlbs. Generally, you'll tighten the barrel nut by hand until it stops, then use your barrel wrench to tighten until the next hole in the nut lines up with the gas tube hole in the receiver. There's not much room for error here as the nut tightens up real quick.
If the hole in the nut is 50% in front of the hole in the receiver at hand tight, use your wrench to tighten and align the holes and you're done. You won't be able to reach the next hole without excessive effort, which will bend your indexing pin and you are now overtorqued.
The bitch with these is when you tighten by hand and just reach or barely pass a hole. Then you put on the wrench and can't reach the next hole. Here, you will need to tighten/loosen 2-3 times to "walk the threads" to reach the next hole. This is why a torque wrench here is oftentimes irrelevent.
Reciever block and bench vise are a must and correct barrel nut or free float tube wrench depending on what you are installing. Moly grease on the reciever threads. You'll need a clip ring wrench if installing a delta ring for standard forend grips. Small punch.
Although the barrels are headspaced by the receiver extension at the manufacturer, it is recemmended to run a go/no go guage after the gun is assemble to assure proper head space. There are also considerations you should read up on if you are mounting the gas block
