Machining AR-15 upper forgings

It takes so long to generate a meaningful post (complete project) that we’re going to try posting progress pics.  Consider these a teaser.  When the project is done, I’ll publish a complete tutorial, with dimensions.  Until then, here’s what we’re working on…

We got some AR-15 upper receiver forgings (both ‘A2 and ‘A3 style).  After quite a bit of planning (these are more difficult than the lower), we’ve started making chips.

Aligning the first setup

Aligning the first setup

After finding a rough center on the thread boss, we install a dowel pin to use as a reference to the bore center line.

Centering pin installed.  Note the fixture plate in the background.

Centering pin installed. Note the fixture plate in the background.

We then setup to cut the deck and lugs:

Setting up to cut the deck and lugs

Setting up to cut the deck and lugs

After much locating work to reference the dowel pin (our centerline), we cut the deck and lugs.

Cutting the deck of the AR upper

Cutting the deck of the AR upper

And in the same setup, cut the lugs to height.

Lugs cut to height.

Lugs cut to height.

To be continued…

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