What is the ID tolerance for the portion of the upper receiver that accepts the barrel extension?
Some are tighter than others...
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What is the ID tolerance for the portion of the upper receiver that accepts the barrel extension?
Some are tighter than others...
1.000" +.002"/-0 for the first 1.110" +.030"/-0
1.000" +.006"/-0 for the remainder.
Is that just measured with a caliper?
Here's you some reading material if interested. https://www.ar15.com/forums/ar-15/-/118-696919/
Not if you want an accurate measurement.
Bore micrometer:
https://images-na.ssl-images-amazon....eL._SX522_.jpg
Or, if you are less extravagant, telescoping gauges and an outside micrometer:
https://m.media-amazon.com/images/I/..._AC_SS450_.jpg
Oh, and the clamping force is nowhere near 10,000 pound as someone stated in that thread.
With properly greased threads the clamping load is 1,800 pounds to 4,800 pounds.
Without properly gauging you don't know. The more guns you get to work on you can definitely start to notice differences.