lazyengineer Wrote:I'm guessing my timing will be off if I screw and torque it back on myself? And also, my headspace would change too?
Thoughts on best route from here?
Lazy,
AA would have headspaced the chamber with the extension torqued up tight.
I have always understood 150ft lbs is the MILSPEC torque for an extension. I read different torques from 100 - 150ft lbs on different forums, more towards 150 however.
I came across this on Homegunsmith forum which discusses how headspace varies between screwed on with no torque, and screwed up to 140.
[INDENT]It's 140 ft-lbs, and you have to kinda wing it - in general about 0.0035" (or two pieces of scotch tape on the back of your headspace gage) is good. If the 'go' guage fits with two pieces of tape on the back, it will likely fit (without the tape) after the extension is torqued into place... you should certainly verify that it's correct, but you can always go back and make small adjustments - like cutting the chamber a few thou deeper by hand if you underestimate, or taking a little off the shoulder if you over estimate.
[/INDENT]
To be clear, you mention "barrel extension", not barrel nut so you mean the extension with bolt lugs and indexing pin that screws onto the barrel and done at the factory, right? Not the barrel nut that screws the barrel and extension into the upper.