Upper Receiver Dimensions

[prepare]

What is the ID tolerance for the portion of the upper receiver that accepts the barrel extension?
Some are tighter than others...

[lysander]

1.000" +.002"/-0 for the first 1.110" +.030"/-0

1.000" +.006"/-0 for the remainder.

[prepare]

1.000" +.002"/-0 for the first 1.110" +.030"/-0

1.000" +.006"/-0 for the remainder.

What are the actual dimensions supposed to be?

[bamashooter]

1.000" +.002"/-0 for the first 1.110" +.030"/-0

1.000" +.006"/-0 for the remainder.

This.

[prepare]

Is that just measured with a caliper?

[Inkslinger]

Is that just measured with a caliper?

My guess would be micrometers or CMM.

[bamashooter]

Here's you some reading material if interested. https://www.ar15.com/forums/ar-15/-/118-696919/

[lysander]

Is that just measured with a caliper?

Not if you want an accurate measurement.

Bore micrometer:

https://images-na.ssl-images-amazon.com/images/I/6177qFD2neL._SX522_.jpg

Or, if you are less extravagant, telescoping gauges and an outside micrometer:

https://m.media-amazon.com/images/I/71JWrrjfYJL._AC_SS450_.jpg


Here's you some reading material if interested. https://www.ar15.com/forums/ar-15/-/118-696919/
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.

[prepare]

Without properly gauging you don't know. The more guns you get to work on you can definitely start to notice differences.

[prepare]

Not if you want an accurate measurement.

Bore micrometer:

https://images-na.ssl-images-amazon.com/images/I/6177qFD2neL._SX522_.jpg

Or, if you are less extravagant, telescoping gauges and an outside micrometer:

https://m.media-amazon.com/images/I/71JWrrjfYJL._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.

Mil-spec barrel nut torque is 30-80 ft lbs. So 1,800 lbs of clamping force is on the lower torque end (30 in lbs) and 4,800 lbs would be on the 80 in lbs side?

[prepare]

Not if you want an accurate measurement.

Bore micrometer:

https://images-na.ssl-images-amazon.com/images/I/6177qFD2neL._SX522_.jpg

Or, if you are less extravagant, telescoping gauges and an outside micrometer:

https://m.media-amazon.com/images/I/71JWrrjfYJL._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.

Mil-spec barrel nut torque is 30-80 ft lbs. So 1,800 lbs of clamping force is on the lower torque end (30 in lbs) and 4,800 lbs would be on the 80 in lbs side?

[lysander]

Yes, that would be correct.